[media] gspca_pac7311: Adjust control scales to match registers

Now that the pac7302 and pac7311 drivers are split, they no longer
share there control settings, so there is no need to scale the controls
to register values, instead make them reflect the registers directly.

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