msm: vidc: Add extradata support

Uncompressed buffers can have extradata associated with
them. This extradata contains information about the
uncompressed buffer, eg: interleaving information,
macroblock error information etc. With this change
extradata buffers can be exchanged between firmware and
client. If the number of planes in a  v4l2 buffer are more
than one, then the last plane is considered as the plane
containing extradata information.

Change-Id: I4659d5a5749b0c1f4e32e17ccd5aecfbc4600f62
Signed-off-by: Vinay Kalia <vkalia@codeaurora.org>