Not only the qx3 microscope has a button, but some cameras too. Tested
with the Trust sp@cecam 100 (and with a creative and ezcam without button).
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>