[media] saa7134: v4l2-compliance: use v4l2_fh to fix priority handling

Make saa7134 driver more V4L2 compliant: remove broken priority handling
and use v4l2_fh instead

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
[hans.verkuil@cisco.com: fixed a merge conflict in saa7134.h]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>