msm: mdss: mdp: update CDM CSC coefficients during HDR playback

On HDR playback, update CDM CSC coefficients from Rec709 to
BT2020, so that RGB will be converted to YUV444 and then to
YUV420 in BT2020 colorspace.
Once HDR playback is done, reset CDM CSC coefficients to default
Rec709 values.

Change-Id: Ib3ab4fb61fc3392d76cf138cc4a20d4bc55ed016
Signed-off-by: Narender Ankam <nankam@codeaurora.org>
Signed-off-by: Ramendra Kumar <ramendra@codeaurora.org>