usb-hub: wakeup on attach

When attaching a new device we must send a wakeup request to the root
hub, otherwise the guest will not notice the new device in case the
usb hub is suspended.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

hw/usb-hub.c

@@ -163,6 +163,7 @@ static void usb_hub_attach(USBPort *port1)
     } else {
         port->wPortStatus &= ~PORT_STAT_LOW_SPEED;
     }
+    usb_wakeup(&s->dev);
 }
 
 static void usb_hub_detach(USBPort *port1)