usb: dwc3: depend on both Host and Gadget stacks

now that we have host support, we must depend
on both sides.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/Kconfig

 config USB_DWC3
 	tristate "DesignWare USB3 DRD Core Support"
-	depends on (USB || USB_GADGET)
+	depends on (USB && USB_GADGET)
 	select USB_OTG_UTILS
 	select USB_GADGET_DUALSPEED
 	select USB_GADGET_SUPERSPEED