[media] vivid: add VBI capture and output code

This adds support for VBI capture (raw and sliced) and VBI output
(raw and sliced) to the vivid driver. In addition a VBI generator
is added that generates simple VBI data in either sliced or raw
format.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>