[media] uvcvideo: fix cropcap v4l2-compliance failure

The v4l2-compliance tool expects that if VIDIOC_CROPCAP is defined, then
VIDIOC_G_SELECTION for TGT_CROP_BOUNDS/DEFAULT is also defined (or COMPOSE
in the case of an output device).

In fact, all that a driver has to do to implement cropcap is to support
those two targets since the v4l2 core will implement cropcap and fill in
the pixelaspect to 1/1 by default.

Implementing cropcap is only needed if the pixelaspect isn't square.

So implement g_selection instead of cropcap in uvc to fix the v4l2-compliance
failure.

[Added blank lines for improved readability]

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>