drivers: usb: wusbcore: Fix dependency for USB_WUSB

Fix the following warning:

warning: (USB_WUSB) selects UWB which has unmet direct dependencies (EXPERIMENTAL && PCI)

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>