[media] v4l2: Add Start Code Search (SCS) control and flag

The Start Code Search (SCS) control set the amount of data that the
codec should search for a start code before returning an error. The
flag inform that no start code was found.

Change-Id: Ic4750feefbd3e3519c365b763b050733a9ba2bf6
Signed-off-by: Jorge Solano Altamirano <jsolano@codeaurora.org>