mm-video-v4l2: venc: Add check for overriding level based on LTR count

When LTR count is set it might be higher than dpb count resulting in
bitstream error or failure in setting LTR in bitstream. This change
updates the level based on LTR count.

CRs-fixed: 640720
Change-Id: Icda3f406517f5685bb39944699fb2d66268c3f4f
1 file changed