usb: chipidea: udc: .pullup is valid only when vbus is there

For chipidea, the IP must know vbus before the controller
begins to run. So the .pullup should only be called when
the vbus is there.
Tested-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/chipidea/udc.c

@@ -1511,6 +1511,9 @@ static int ci_udc_pullup(struct usb_gadget *_gadget, int is_on)
 {
 	struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
 
+	if (!ci->vbus_active)
+		return -EOPNOTSUPP;
+
 	if (is_on)
 		hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS);
 	else