[media] V4L: ov9740: Add suspend/resume

On suspend, remember whether we are streaming or not, and at what frame format,
so that on resume, we can start streaming again.

Signed-off-by: Andrew Chew <achew@nvidia.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>