[media] gspca - ov519: Change the ov519 start and stop sequences

- start and stop streaming are done via the FRAR
- streaming suspend (for control change) is done by video reset

Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>