msm: vidc: rewrite v4l2 cluster construction

V4L2 framework has limitation of not supporting
same control in multiple clusters. Overcome this
limitation by grouping all controls into one
super cluster.

Change-Id: I974199e1388a1b33ae5e56edd4b0af712eb9babf
Signed-off-by: Arun Menon <avmenon@codeaurora.org>