drm/sun4i: csc: Add support for the new MMIO layout

D1 changes the MMIO offsets for the CSC blocks in the first mixer. The
mixers' ccsc property is used as an index into the ccsc_base array. Use
an enumeration to describe this index, and add the new set of offsets.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220424162633.12369-11-samuel@sholland.org