[media] gspca_zc3xx: Convert to the control framework

The initial version was done by HV, corrections were made by HdG, and some
final small changes again by HV.

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