V4L/DVB (12093): gspca_sonixj: Name saturation control saturation, not color

Name saturation control saturation, not color and make the default
less saturated (the old default was overdoing it).

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