msm: vidc: Expose extradata size to userspace

Previously, the extradata size was included within VENUS_BUFFER_SIZE
and callers (primarily in userspace) wouldn't know how much extra
padding was added to the buffer size. Exposing it allows userspace to
query directly instead of doing guesswork.

Change-Id: I7f9701a4adfe364d757028514bdd4fa84402a995
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>

Conflicts:
	include/media/msm_media_info.h
msm: vidc: Add AFD and CC metadata support to extradata

Add support and control for setting Active format
description and closed caption meta data in the
extradata. FW parses metadata and adds it to the
extradata. Client can use control to parse extradata
for the metadata information.

Change-Id: I79fb71e635927c95e0792862c9dea7d96f58e895
Signed-off-by: Jayasena Sangaraboina <jsanga@codeaurora.org>