usb: wusbcore: USB_WUSB_CBAF depends on USB

Add USB build dependency for USB_WUSB_CBAF.

Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/wusbcore/Kconfig

@@ -17,6 +17,7 @@ config USB_WUSB
 
 config USB_WUSB_CBAF
 	tristate "Support WUSB Cable Based Association (CBA)"
+	depends on USB
 	help
 	  Some WUSB devices support Cable Based Association. It's used to
 	  enable the secure communication between the host and the