drm/ingenic: Use fbdev-dma

Implement fbdev emulation with fbdev-dma. Fbdev-dma now supports
damage handling, which is required by ingenic. Avoids the overhead of
fbdev-generic's additional shadow buffering. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Paul Cercueil <paul@crapouillou.net>
Acked-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20240419083331.7761-26-tzimmermann@suse.de