V4L/DVB (8512): gspca: Do not use the driver_info field of usb_device_id.

The field driver_info will be used to handle the specific per webcam
information.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>