drm/rockchip: dsi: Add rv1126 MIPI DSI support

RV1126 MIPI DSI supports V1.2 DPHY with 4 lanes and 1Gbps transfer
rate for lane.

Add support for it.

Signed-off-by: Jagan Teki <jagan@edgeble.ai>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230731110012.2913742-9-jagan@edgeble.ai