[MERGED] drm/panel: add Raydium RM67200 panel driver

The Rockchip W552793DBA-V10 display/touchscreen board contains a
Wanchanglong W552793BAA panel, which in turn is using a Raydium
RM67200 MIPI-DSI controller. Add a DSI panel driver for it.

The W552793BAA panel init sequence has been taken from the RK3588
EVB1 vendor kernel devicetree.

Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Reviewed-by: Andy Yan <andyshrk@163.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>