Documentation: ABI: testing: mt6360: Add ADC sysfs guideline

Add ABI documentation for mt6360 ADC sysfs interfaces.
Signed-off-by: Gene Chen <gene_chen@richtek.com>
Link: https://lore.kernel.org/r/1603181267-15610-3-git-send-email-gene.chen.richtek@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/ABI/testing/sysfs-bus-iio-adc-mt6360

+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage0_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 USBID ADC which connected to connector ID pin.
+		Calculating with scale and offset returns voltage in uV
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage1_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 VBUS ADC with lower accuracy(+-75mA)
+		higher measure range(1~22mV)
+		Calculating with scale and offset returns voltage in uV
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage2_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 VBUS ADC with higher accuracy(+-30mA)
+		lower measure range(1~9.76V)
+		Calculating with scale and offset returns voltage in uV
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage3_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 VSYS ADC
+		Calculating with scale and offset returns voltage in uV
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage4_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 VBAT ADC
+		Calculating with scale and offset returns voltage in uV
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_current5_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 IBUS ADC
+		Calculating with scale and offset returns voltage in uA
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_current6_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 IBAT ADC
+		Calculating with scale and offset returns voltage in uA
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_current7_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 CHG_VDDP ADC
+		Calculating with scale and offset returns voltage in uV
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_temp8_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 IC junction temperature
+		Calculating with scale and offset returns temperature in degree
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage9_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 VREF_TS ADC
+		Calculating with scale and offset returns voltage in uV
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_voltage10_raw
+KernelVersion:	5.8.0
+Contact:	gene_chen@richtek.com
+Description:
+		Indicated MT6360 TS ADC
+		Calculating with scale and offset returns voltage in uV