edp: change array base address

Per feedback from qcom, PD_CTL is at offset of 0x4 from the start of the
array element.

The math works out the same for now, but this would matter if more
registers are added.
rnndb: Add registers for msm YUV support

Note:
chroma_samp_type can be used by both MDP4 and MDP5, thus
moved to mdp_common.

Signed-off-by: Stephane Viau <sviau@codeaurora.org>
a4xx: more updates