[media] se401: deprecate driver, move to staging

The se401 driver is deprecated and is moved to staging. If no one will
convert this driver to V4L2, then it will be removed in 2.6.39.

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