[media] ov9640: fix missing break

Without this rev2 ends up behaving as rev3

Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=44081



Reported-by:  <dcb314@hotmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>