V4L/DVB (11022): zoran/bt819: use new notify functionality.

Bt819 needs the parent driver to drive a GPIO pin low and high in order to
reset its fifo. Use the new notify callback for this.

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