drm/panel: st7701: Add Anbernic RG-ARC Panel Support

The Powkiddy RG-ARC is a series of 2 handheld devices, each with a 4
inch 480x640 display. Add support for the display.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20231208154847.130615-4-macroalpha82@gmail.com


Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231208154847.130615-4-macroalpha82@gmail.com