drm/ingenic: Add support for the JZ4760(B)

Add support for the JZ4760 and JZ4760B SoCs to the ingenic-drm display
driver.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220708205406.96473-4-paul@crapouillou.net