Since we are not using v4l2_device_call_* calls any more, we don't need to
initialise subdevice .grp_id any more. This also fixes compiler warnings on
64-bit platforms.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>