media: dt-bindings: media: rcar_vin: add device tree support for r8a7744

Add compatible strings for r8a7744. No driver change is needed as
"renesas,rcar-gen2-vin" will activate the right code.However, it is good
practice to document compatible strings for the specific SoC as this
allows SoC specific changes to the driver if needed, in addition to
document SoC support and therefore allow checkpatch.pl to validate
compatible string values.

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/devicetree/bindings/media/rcar_vin.txt

@@ -11,6 +11,7 @@ on Gen3 platforms to a CSI-2 receiver.
 
  - compatible: Must be one or more of the following
    - "renesas,vin-r8a7743" for the R8A7743 device
+   - "renesas,vin-r8a7744" for the R8A7744 device
    - "renesas,vin-r8a7745" for the R8A7745 device
    - "renesas,vin-r8a7778" for the R8A7778 device
    - "renesas,vin-r8a7779" for the R8A7779 device