[media] uvcvideo: Set device_caps in VIDIOC_QUERYCAP

Set the capabilities field to global capabilities, and the device_caps
field to the video node capabilities.
This issue was found by the v4l2-compliance tool.

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