usb: xhci-mtk: resume USB3 roothub first

Give USB3 devices a better chance to enumerate at USB3 speeds if
they are connected to a suspended host.
Porting from "671ffdff5b13 xhci: resume USB 3 roothub first"

Cc: <[e-mail]>
Signed-off-by: Chunfeng Yun <[e-mail]>
Signed-off-by: Mathias Nyman <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/host/xhci-mtk.c

···
 	xhci_mtk_host_enable(mtk);
 
 	xhci_dbg(xhci, "%s: restart port polling\n", __func__);
-	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
-	usb_hcd_poll_rh_status(hcd);
 	set_bit(HCD_FLAG_POLL_RH, &xhci->shared_hcd->flags);
 	usb_hcd_poll_rh_status(xhci->shared_hcd);
+	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+	usb_hcd_poll_rh_status(hcd);
 	return 0;
 }