arm64: dts: renesas: draak: Describe CVBS input

arm64: dts: renesas: draak: Describe CVBS input

Describe CVBS video input through analog video decoder ADV7180
connected to video input interface VIN4.

The video input signal path is shared with HDMI video input, and
selected by on-board switches SW-53 and SW-54 with CVBS input selected
by the default switches configuration.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>