[media] v4l2-ioctl: call g_selection before calling cropcap

If the vidioc_cropcap op is implemented by the driver then the v4l2
core will call that directly.

If g_selection is available, then the core cropcap implementation
uses g_selection to fill in the bounds and defrect and it sets the
pixelaspect to 1x1.

But if both are available, then I would like to use g_selection to
fill in defrect and bounds before calling cropcap. That way the
driver's cropcap implementation doesn't have to set defrect or
bounds.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>