dt-bindings: soc: rockchip: grf: add rockchip,lvds.yaml

Add new converted rockchip,lvds.yaml to grf.yaml file.
Prepare for more SoCs with lvds output.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/ff3644da-e5ae-f795-c7d9-454b8c8bdfe8@gmail.com