Deprecate the cpia2 driver. This driver does not use the vb2 framework
for video streaming, instead it implements its own version.

We want to get rid of these old drivers, so deprecated it for future
removal.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>