dt-bindings: iio: BU27034 => BU27034ANUC

The BU27034NUC was cancelled before it entered mass production. It was
replaced by a new variant BU27034ANUC (note, added 'A'). The new
variant gained a few significant changes, like removal of the 3.rd data
channel and dropping some of the gain settings. This means that, from
software point of view these ICs are incompatible. Lux calculation based
on the data from the sensors needs to be done differently, and on the
BU27034ANUC the channel 3 data is missing. Also, the gain setting
differencies matter.

Unfortunately, the identification register was not changed so there is no
safe way for the software to distinguish the variants.

According to the ROHM HQ engineers, the old BU27034NUC should not be
encountered in the wild. Hence it makes sense to remove the support for
the old BU27034NUC and add support for the new BU27034ANUC. Change the
compatible in order to not load the incompatible old driver for new sensor
(or, if someone had the old sensor, the new driver for it).

Drop the compatible for old sensor which should not be in the wild and
add a new compatible for the new model with accurate model suffix
'anuc'.  Rename the file to match the new compatible.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/c39f9c67b3c07a27d7a13109c7b69cff9cfd2b9b.1720176341.git.mazziesaccount@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/light/rohm,bu27034.yaml → Documentation/devicetree/bindings/iio/light/rohm,bu27034anuc.yaml

 # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
 %YAML 1.2
 ---
-$id: http://devicetree.org/schemas/iio/light/rohm,bu27034.yaml#
+$id: http://devicetree.org/schemas/iio/light/rohm,bu27034anuc.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: ROHM BU27034 ambient light sensor
+title: ROHM BU27034ANUC ambient light sensor
 
 maintainers:
   - Matti Vaittinen <mazziesaccount@gmail.com>
 
 description: |
-  ROHM BU27034 is an ambient light sesnor with 3 channels and 3 photo diodes
+  ROHM BU27034ANUC is an ambient light sensor with 2 channels and 2 photo diodes
   capable of detecting a very wide range of illuminance. Typical application
   is adjusting LCD and backlight power of TVs and mobile phones.
-  https://fscdn.rohm.com/en/products/databook/datasheet/ic/sensor/light/bu27034nuc-e.pdf
 
 properties:
   compatible:
-    const: rohm,bu27034
+    const: rohm,bu27034anuc
 
   reg:
     maxItems: 1
@@ -37,7 +36,7 @@ examples:
       #size-cells = <0>;
 
       light-sensor@38 {
-        compatible = "rohm,bu27034";
+        compatible = "rohm,bu27034anuc";
         reg = <0x38>;
         vdd-supply = <&vdd>;
       };