media: dt-bindings: rcar-vin: Add R8A77990 support

Add compatible string for R-Car E3 R8A77990 to the list of SoCs supported by
rcar-vin driver.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/devicetree/bindings/media/rcar_vin.txt

@@ -24,6 +24,7 @@ on Gen3 platforms to a CSI-2 receiver.
    - "renesas,vin-r8a7796" for the R8A7796 device
    - "renesas,vin-r8a77965" for the R8A77965 device
    - "renesas,vin-r8a77970" for the R8A77970 device
+   - "renesas,vin-r8a77990" for the R8A77990 device
    - "renesas,vin-r8a77995" for the R8A77995 device
    - "renesas,rcar-gen2-vin" for a generic R-Car Gen2 or RZ/G1 compatible
      device.