usb: dwc2: Clear GINTSTS_RESTOREDONE bit after restore is generated.

When hibernation exit is performed the dwc2_hib_restore_common()
function is called. In that function we wait until GINTSTS_RESTOREDONE
bit is set. However, after the setting of that bit we get a lot of
(dwc2_hsotg_irq:) interrupts which indicates that (GINTSTS.RstrDoneInt)
restore done interrupt is asserted.

To avoid restore done interrupt storm after restore is generated
clear GINTSTS_RESTOREDONE bit in GINTSTS register.
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Link: https://lore.kernel.org/r/20210416124739.D6269A005D@mailhost.synopsys.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc2/core.c

@@ -299,6 +299,12 @@ void dwc2_hib_restore_common(struct dwc2_hsotg *hsotg, int rem_wakeup,
 			__func__);
 	} else {
 		dev_dbg(hsotg->dev, "restore done  generated here\n");
+
+		/*
+		 * To avoid restore done interrupt storm after restore is
+		 * generated clear GINTSTS_RESTOREDONE bit.
+		 */
+		dwc2_writel(hsotg, GINTSTS_RESTOREDONE, GINTSTS);
 	}
 }