[media] media: adv7604: document support for ADV7612 dual HDMI input decoder

This documentation accompanies the patch adding support for the ADV7612
dual HDMI decoder / repeater chip.
Signed-off-by: Ian Molton <ian.molton@codethink.co.uk>
Reviewed-by: William Towle <william.towle@codethink.co.uk>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Documentation/devicetree/bindings/media/i2c/adv7604.txt

-* Analog Devices ADV7604/11 video decoder with HDMI receiver
+* Analog Devices ADV7604/11/12 video decoder with HDMI receiver
 
-The ADV7604 and ADV7611 are multiformat video decoders with an integrated HDMI
-receiver. The ADV7604 has four multiplexed HDMI inputs and one analog input,
-and the ADV7611 has one HDMI input and no analog input.
+The ADV7604 and ADV7611/12 are multiformat video decoders with an integrated
+HDMI receiver. The ADV7604 has four multiplexed HDMI inputs and one analog
+input, and the ADV7611 has one HDMI input and no analog input. The 7612 is
+similar to the 7611 but has 2 HDMI inputs.
 
-These device tree bindings support the ADV7611 only at the moment.
+These device tree bindings support the ADV7611/12 only at the moment.
 
 Required Properties:
 
   - compatible: Must contain one of the following
     - "adi,adv7611" for the ADV7611
+    - "adi,adv7612" for the ADV7612
 
   - reg: I2C slave address
 
@@ -22,10 +24,10 @@ port, in accordance with the video interface bindings defined in
 Documentation/devicetree/bindings/media/video-interfaces.txt. The port nodes
 are numbered as follows.
 
-  Port			ADV7611
+  Port			ADV7611    ADV7612
 ------------------------------------------------------------
-  HDMI			0
-  Digital output	1
+  HDMI			0             0, 1
+  Digital output	1                2
 
 The digital output port node must contain at least one endpoint.