power/qemu: emulate USB 3.0 with -device qemu-xhci

The special qemu-xhci device emulates USB 3.0 and comes with a much more
virtualization-friendly design: this results in a significant performance
improvement (noticeable when installing Operating Systems from USB)

Signed-off-by: Cedric Hombourger <cedric.hombourger@siemens.com>

mtda/power/qemu.py

@@ -155,7 +155,7 @@ def start(self):
         options += " -device e1000,netdev=net0"
         options += " -netdev user,id=net0,"
         options += "hostfwd=tcp::2222-:22,hostname={0}".format(self.hostname)
-        options += " -usb"
+        options += " -device qemu-xhci"
         options += " -vnc :0,websocket=on"
 
         # extra options