usb: gadget: ci13xxx_pci: guard against devices without driver_data

Don't try to initialize devices that don't have driver_data assigned
to their pci ids.

Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>