[media] vivid: add xfer_func support

Add support for the transfer function: create a new control for it,
and support it for both capture and output sides.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
7 files changed