[media] gspca_sonixb: Fix exposure control min/max value for coarse expo sensors

This got broken by some gscpa core fixes, this patch restores the proper
min/max values for these controls.

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