media: vivid: Add metadata output support

Support metadata output in vivid driver.
Metadata output is used to set brightness, contrast, saturation
and hue.
Adds new files for metadata output.

Signed-off-by: Vandana BN <bnvandana@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>