drm/ingenic: Support handling different pixel formats in F0/F1 planes

Until now the ingenic-drm driver supported the same pixel formats on the
F0 and F1 planes, and across all SoCs. However, the F0 plane does support
paletted 8bpp, while the F1 plane doesn't.

Furthermore, the three SoCs currently supported all have different pixel
formats available; 24bpp was added in JZ4725B, 30bpp was added in
JZ4770.

Prepare the inclusion of paletted 8bpp, 24bpp and 30bpp support by
having separate pixel format lists for F0 and F1 planes.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200926170501.1109197-5-paul@crapouillou.net