msm: vidc: Adds VUI timing info support for AVC encoding.

Poor video quality is observed as VUI fps information is not present in
the encoded bit stream. Add support for VUI timing info in video driver
and an additional V4L2 control to set from user space.

Change-Id: I3594903cb897920ea2ef93208644ac8c6ca5d5d9
CRs-Fixed: 399017
Signed-off-by: Srinu Gorle <sgorle@codeaurora.org>