drm/panel: st7703: Add Powkiddy RGB10MAX3 Panel Support

The Powkiddy RGB10MAX3 is a handheld device with a 5 inch 720x1280
display panel with a Sitronix ST7703 display controller. The panel
is installed rotated 270 degrees.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240212184950.52210-3-macroalpha82@gmail.com