usb: gadget: pch_udc: Fix USB suspend issue

ISSUE:
After USB Suspend, a system rarely freezes.

CAUSE:
When USB Suspend occurred, the driver is not notifying
a gadget of the event.
Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/pch_udc.c

@@ -2475,8 +2475,15 @@ static void pch_udc_dev_isr(struct pch_udc_dev *dev, u32 dev_intr)
 	if (dev_intr & UDC_DEVINT_SC)
 		pch_udc_svc_cfg_interrupt(dev);
 	/* USB Suspend interrupt */
-	if (dev_intr & UDC_DEVINT_US)
+	if (dev_intr & UDC_DEVINT_US) {
+		if (dev->driver
+			&& dev->driver->suspend) {
+			spin_unlock(&dev->lock);
+			dev->driver->suspend(&dev->gadget);
+			spin_lock(&dev->lock);
+		}
 		dev_dbg(&dev->pdev->dev, "USB_SUSPEND\n");
+	}
 	/* Clear the SOF interrupt, if enabled */
 	if (dev_intr & UDC_DEVINT_SOF)
 		dev_dbg(&dev->pdev->dev, "SOF\n");