docs: ABI: sysfs-class-backlight: unify ambient light zone nodes

./scripts/get_abi.pl is warning about duplicated symbol
definition:

	Warning: /sys/class/backlight/<backlight>/l1_daylight_max is defined 2 times:  ./Documentation/ABI/testing/sysfs-class-backlight-driver-adp8870:4  ./Documentation/ABI/testing/sysfs-class-backlight-adp8860:12

What happens is that 3 drivers use the same pattern to report
max and dim setting for different ambient light zones.

It should be noticed that the adp8870 doc was missing an
entry for l1_daylight_dim, which was fixed on this patch.

While the ambient light zone is device-specific, the sysfs
definition is actually common. So, unify them at:

	Documentation/ABI/testing/sysfs-class-backlight

and use as the contact point, the e-mail reported by
get_maintainers.pl for the subsystem.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/c13c6ebd03cd04a0d15d89018f8d529918fc0a73.1621413933.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/ABI/testing/sysfs-class-backlight

@@ -84,3 +84,103 @@ Description:
 		It can be enabled by writing the value stored in
 		/sys/class/backlight/<backlight>/max_brightness to
 		/sys/class/backlight/<backlight>/brightness.
+
+What:		/sys/class/backlight/<backlight>/<ambient light zone>_max
+Date:		Sep, 2009
+KernelVersion:	v2.6.32
+Contact:	device-drivers-devel@blackfin.uclinux.org
+Description:
+		Control the maximum brightness for <ambient light zone>
+		on this <backlight>. Values are between 0 and 127. This file
+		will also show the brightness level stored for this
+		<ambient light zone>.
+
+		The <ambient light zone> is device-driver specific:
+
+		For ADP5520 and ADP5501, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		daylight     /sys/class/backlight/<backlight>/daylight_max
+		office       /sys/class/backlight/<backlight>/office_max
+		dark         /sys/class/backlight/<backlight>/dark_max
+		===========  ================================================
+
+		For ADP8860, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_max
+		l2_office    /sys/class/backlight/<backlight>/l2_office_max
+		l3_dark      /sys/class/backlight/<backlight>/l3_dark_max
+		===========  ================================================
+
+		For ADP8870, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_max
+		l2_bright    /sys/class/backlight/<backlight>/l2_bright_max
+		l3_office    /sys/class/backlight/<backlight>/l3_office_max
+		l4_indoor    /sys/class/backlight/<backlight>/l4_indoor_max
+		l5_dark      /sys/class/backlight/<backlight>/l5_dark_max
+		===========  ================================================
+
+		See also: /sys/class/backlight/<backlight>/ambient_light_zone.
+
+What:		/sys/class/backlight/<backlight>/<ambient light zone>_dim
+Date:		Sep, 2009
+KernelVersion:	v2.6.32
+Contact:	device-drivers-devel@blackfin.uclinux.org
+Description:
+		Control the dim brightness for <ambient light zone>
+		on this <backlight>. Values are between 0 and 127, typically
+		set to 0. Full off when the backlight is disabled.
+		This file will also show the dim brightness level stored for
+		this <ambient light zone>.
+
+		The <ambient light zone> is device-driver specific:
+
+		For ADP5520 and ADP5501, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		daylight     /sys/class/backlight/<backlight>/daylight_dim
+		office       /sys/class/backlight/<backlight>/office_dim
+		dark         /sys/class/backlight/<backlight>/dark_dim
+		===========  ================================================
+
+		For ADP8860, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_dim
+		l2_office    /sys/class/backlight/<backlight>/l2_office_dim
+		l3_dark      /sys/class/backlight/<backlight>/l3_dark_dim
+		===========  ================================================
+
+		For ADP8870, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_dim
+		l2_bright    /sys/class/backlight/<backlight>/l2_bright_dim
+		l3_office    /sys/class/backlight/<backlight>/l3_office_dim
+		l4_indoor    /sys/class/backlight/<backlight>/l4_indoor_dim
+		l5_dark      /sys/class/backlight/<backlight>/l5_dark_dim
+		===========  ================================================
+
+		See also: /sys/class/backlight/<backlight>/ambient_light_zone.
+

Documentation/ABI/testing/sysfs-class-backlight-adp5520

-sysfs interface for analog devices adp5520(01) backlight driver
----------------------------------------------------------------
-
-The backlight brightness control operates at three different levels for the
-adp5520 and adp5501 devices: daylight (level 1), office (level 2) and dark
-(level 3). By default the brightness operates at the daylight brightness level.
-
-What:		/sys/class/backlight/<backlight>/daylight_max
-What:		/sys/class/backlight/<backlight>/office_max
-What:		/sys/class/backlight/<backlight>/dark_max
-Date:		Sep, 2009
-KernelVersion:	v2.6.32
-Contact:	Michael Hennerich <michael.hennerich@analog.com>
-Description:
-		(RW) Maximum current setting for the backlight when brightness
-		is at one of the three levels (daylight, office or dark). This
-		is an input code between 0 and 127, which is transformed to a
-		value between 0 mA and 30 mA using linear or non-linear
-		algorithms.
-
-What:		/sys/class/backlight/<backlight>/daylight_dim
-What:		/sys/class/backlight/<backlight>/office_dim
-What:		/sys/class/backlight/<backlight>/dark_dim
-Date:		Sep, 2009
-KernelVersion:	v2.6.32
-Contact:	Michael Hennerich <michael.hennerich@analog.com>
-Description:
-		(RW) Dim current setting for the backlight when brightness is at
-		one of the three levels (daylight, office or dark). This is an
-		input code between 0 and 127, which is transformed to a value
-		between 0 mA and 30 mA using linear or non-linear algorithms.

Documentation/ABI/testing/sysfs-class-backlight-adp8860

-sysfs interface for analog devices adp8860 backlight driver
------------------------------------------------------------
-
-The backlight brightness control operates at three different levels for the
-adp8860, adp8861 and adp8863 devices: daylight (level 1), office (level 2) and
-dark (level 3). By default the brightness operates at the daylight brightness
-level.
-
-See also /sys/class/backlight/<backlight>/ambient_light_level and
-/sys/class/backlight/<backlight>/ambient_light_zone.
-
-
-What:		/sys/class/backlight/<backlight>/l1_daylight_max
-What:		/sys/class/backlight/<backlight>/l2_office_max
-What:		/sys/class/backlight/<backlight>/l3_dark_max
-Date:		Apr, 2010
-KernelVersion:	v2.6.35
-Contact:	Michael Hennerich <michael.hennerich@analog.com>
-Description:
-		(RW) Maximum current setting for the backlight when brightness
-		is at one of the three levels (daylight, office or dark). This
-		is an input code between 0 and 127, which is transformed to a
-		value between 0 mA and 30 mA using linear or non-linear
-		algorithms.
-
-
-What:		/sys/class/backlight/<backlight>/l1_daylight_dim
-What:		/sys/class/backlight/<backlight>/l2_office_dim
-What:		/sys/class/backlight/<backlight>/l3_dark_dim
-Date:		Apr, 2010
-KernelVersion:	v2.6.35
-Contact:	Michael Hennerich <michael.hennerich@analog.com>
-Description:
-		(RW) Dim current setting for the backlight when brightness is at
-		one of the three levels (daylight, office or dark). This is an
-		input code between 0 and 127, which is transformed to a value
-		between 0 mA and 30 mA using linear or non-linear algorithms.

Documentation/ABI/testing/sysfs-class-backlight-driver-adp8870

-See also /sys/class/backlight/<backlight>/ambient_light_level and
-/sys/class/backlight/<backlight>/ambient_light_zone.
-
-What:		/sys/class/backlight/<backlight>/<ambient light zone>_max
-What:		/sys/class/backlight/<backlight>/l1_daylight_max
-What:		/sys/class/backlight/<backlight>/l2_bright_max
-What:		/sys/class/backlight/<backlight>/l3_office_max
-What:		/sys/class/backlight/<backlight>/l4_indoor_max
-What:		/sys/class/backlight/<backlight>/l5_dark_max
-Date:		May 2011
-KernelVersion:	3.0
-Contact:	device-drivers-devel@blackfin.uclinux.org
-Description:
-		Control the maximum brightness for <ambient light zone>
-		on this <backlight>. Values are between 0 and 127. This file
-		will also show the brightness level stored for this
-		<ambient light zone>.
-
-What:		/sys/class/backlight/<backlight>/<ambient light zone>_dim
-What:		/sys/class/backlight/<backlight>/l2_bright_dim
-What:		/sys/class/backlight/<backlight>/l3_office_dim
-What:		/sys/class/backlight/<backlight>/l4_indoor_dim
-What:		/sys/class/backlight/<backlight>/l5_dark_dim
-Date:		May 2011
-KernelVersion:	3.0
-Contact:	device-drivers-devel@blackfin.uclinux.org
-Description:
-		Control the dim brightness for <ambient light zone>
-		on this <backlight>. Values are between 0 and 127, typically
-		set to 0. Full off when the backlight is disabled.
-		This file will also show the dim brightness level stored for
-		this <ambient light zone>.