media: dt-bindings: adv748x: make data-lanes property mandatory for CSI-2 endpoints

media: dt-bindings: adv748x: make data-lanes property mandatory for CSI-2 endpoints

The CSI-2 transmitters can use a different number of lanes to transmit
data. Make the data-lanes mandatory for the endpoints that describe the
transmitters as no good default can be set to fallback on.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>