v4l2: Adds support for codec config

Adds support for codec config flag to be passed
to driver. This flag indicates that the buffer
associated contains codec specific data.

Change-Id: I80cfedc02dfc1efc8727f97e90ac2100e47d2f2a
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>