usb: dwc3: gadget: use udc-core's reset notifier

Replace usb_gadget_driver's disconnect with udc-core's reset notifier at
bus reset handler.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/gadget.c

@@ -2041,6 +2041,17 @@ static void dwc3_resume_gadget(struct dwc3 *dwc)
 	if (dwc->gadget_driver && dwc->gadget_driver->resume) {
 		spin_unlock(&dwc->lock);
 		dwc->gadget_driver->resume(&dwc->gadget);
+	}
+}
+
+static void dwc3_reset_gadget(struct dwc3 *dwc)
+{
+	if (!dwc->gadget_driver)
+		return;
+
+	if (dwc->gadget.speed != USB_SPEED_UNKNOWN) {
+		spin_unlock(&dwc->lock);
+		usb_gadget_udc_reset(&dwc->gadget, dwc->gadget_driver);
 		spin_lock(&dwc->lock);
 	}
 }
@@ -2185,11 +2196,7 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
 			dwc3_gadget_disconnect_interrupt(dwc);
 	}
 
-	/* after reset -> Default State */
-	usb_gadget_set_state(&dwc->gadget, USB_STATE_DEFAULT);
-
-	if (dwc->gadget.speed != USB_SPEED_UNKNOWN)
-		dwc3_disconnect_gadget(dwc);
+	dwc3_reset_gadget(dwc);
 
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
 	reg &= ~DWC3_DCTL_TSTCTRL_MASK;