drm/msm/sde: check dynamic metadata header and adjust payload

Validate the VSIF type code in the dynamic metadata payload and
adjust the payload data programmed in the memory pool to align
with the Infoframe SDP v1.3 VSIF packet type. Also reduce the
size of the static array used for caching payloads.

Change-Id: I33a7ace913c9903aeb02677722973edb2fc2739c
Signed-off-by: Steve Cohen <cohens@codeaurora.org>