mm-video-v4l2: vidc: Populate buffer requirements in C2D

During C2D conversion, encoder sets output format, but doesn't
populate buffer requirements. This behavior results in stale value
of num_planes and causes failure if extradata is enabled.

CRs-Fixed: 1067405
Change-Id: If847a594b579907faa9d89c6992746757a94fc88
1 file changed