drm/ingenic: Upload palette before frame

drm/ingenic: Upload palette before frame

When using C8 color mode, make sure that the palette is always uploaded
before a frame; otherwise the very first frame will have wrong colors.

Do that by changing the link order of the DMA descriptors.

v3: Fix ingenic_drm_get_new_priv_state() called instead of
    ingenic_drm_get_priv_state()

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20211026181240.213806-6-paul@crapouillou.net
Tested-by: Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: Christophe Branchereau <cbranchereau@gmail.com>