dt-bindings: iio: light: add vcnl4040 devicetree bindings

Document the vishay VCNL4040 devicetree bindings.
Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/light/vcnl4000.txt

 VISHAY VCNL4000 -  Ambient Light and proximity sensor
 
-This driver supports the VCNL4000/10/20 and VCNL4200 chips
+This driver supports the VCNL4000/10/20/40 and VCNL4200 chips
 
 Required properties:
 
@@ -8,11 +8,13 @@ Required properties:
         vishay,vcnl4000
         vishay,vcnl4010
         vishay,vcnl4020
+        vishay,vcnl4040
         vishay,vcnl4200
 
 	-reg: I2C address of the sensor, should be one from below based on the model:
         0x13
         0x51
+        0x60
 
 Example: