drm/msm/sde: avoid programming HDR metadata before commit kickoff

Don't program the HDR HW registers during set property as this can
potentially lead to NOC errors.  Instead, cache the data and then
apply to the HW during the kickoff phase.

Change-Id: I986776a043c92beda3e586cd7d29a190169eb6af
Signed-off-by: Steve Cohen <cohens@codeaurora.org>