drm/msm/dp: set bpp and cc values correctly

DP_MISC1_MISC0 register was retaining its previous
bit_depth and colorimetry values. Set only current
values of bit_depth and cc values.

Change-Id: I806ae2bd4b7e615d02286c9d00226537656d26f4
Signed-off-by: Narender Ankam <nankam@codeaurora.org>