dt-bindings: iio: light: as73211: add support for as7331

This device has the same properties and I2C addresses as the as73211.
The only difference between them is the photodiodes they use internally,
which in this case is irrelevant for the bindings.

Acked-by: Conor Dooley <[e-mail]>
Signed-off-by: Javier Carrasco <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

Documentation/devicetree/bindings/iio/light/ams,as73211.yaml

···
 $id: http://devicetree.org/schemas/iio/light/ams,as73211.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: AMS AS73211 JENCOLOR(R) Digital XYZ Sensor
+title: AMS AS73211 JENCOLOR(R) Digital XYZ Sensor and AMS AS7331 UV Sensor
 
 maintainers:
   - Christian Eggers <[e-mail]>
 
 description: |
-  XYZ True Color Sensor with I2C Interface
+  AMS AS73211 XYZ True Color Sensor with I2C Interface
   https://ams.com/documents/20143/36005/AS73211_DS000556_3-01.pdf/a65474c0-b302-c2fd-e30a-c98df87616df
+  AMS AS7331 UVA, UVB and UVC Sensor with I2C Interface
+  https://ams.com/documents/20143/9106314/AS7331_DS001047_4-00.pdf
 
 properties:
   compatible:
     enum:
       - ams,as73211
+      - ams,as7331
 
   reg:
     description: