[media] feature-removal: update V4L1 removal status

While the V4L1 compatibility module has been removed, we still have
two V4L1 drivers that prevent full V4L1 removal.

Those drivers have been moved to staging and will be removed in 2.6.39,
together with the last V4L1 support.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>