[media] bttv: Add Adlink MPG24 entry to the bttv cardlist

Add a proper card entry for this device, rather than abusing entries that are
not-quite-right.
Regards,
	Hans

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>