V4L/DVB: gspca_ov519: Add support for the button on ov518 based cams

Due to hardware limitations this only works while the camera is
streaming.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
1 file changed