usb: dwc2: gadget: register gadget handle to the phy

Bind peripheral controller to the phy on udc_start. Unbind on
udc_stop.
Tested-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc2/gadget.c

@@ -2878,6 +2878,8 @@ static int s3c_hsotg_udc_start(struct usb_gadget *gadget,
 	}
 
 	s3c_hsotg_phy_enable(hsotg);
+	if (!IS_ERR_OR_NULL(hsotg->uphy))
+		otg_set_peripheral(hsotg->uphy->otg, &hsotg->gadget);
 
 	spin_lock_irqsave(&hsotg->lock, flags);
 	s3c_hsotg_init(hsotg);
@@ -2927,6 +2929,8 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget)
 
 	spin_unlock_irqrestore(&hsotg->lock, flags);
 
+	if (!IS_ERR_OR_NULL(hsotg->uphy))
+		otg_set_peripheral(hsotg->uphy->otg, NULL);
 	s3c_hsotg_phy_disable(hsotg);
 
 	regulator_bulk_disable(ARRAY_SIZE(hsotg->supplies), hsotg->supplies);