usb: renesas_usbhs: fixup signal the driver that cable was disconnected

current renesas_usbhs is using new style udc_start/stop from
af1d7056
(usb: gadget: renesas: convert to new style).

cable disconnected signal was needed.
This patch fixup it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/renesas_usbhs/mod_gadget.c

@@ -805,6 +805,13 @@ static int usbhsg_start(struct usbhs_priv *priv)
 
 static int usbhsg_stop(struct usbhs_priv *priv)
 {
+	struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
+
+	/* cable disconnect */
+	if (gpriv->driver &&
+	    gpriv->driver->disconnect)
+		gpriv->driver->disconnect(&gpriv->gadget);
+
 	return usbhsg_try_stop(priv, USBHSG_STATUS_STARTED);
 }