arm64: dts: renesas: salvator-common: Add ADV7482 support

The Salvator boards use an ADV7482 receiver for HDMI and CVBS inputs.

Provide ADV7482 node on the i2c4 bus, along with connectors for the
hdmi and cvbs inputs, and link to the csi20 and csi40 nodes as outputs.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>