r2d: Don't use legacy -usbdevice support for setting up board

It's tempting, because usbdevice_create() is so simple to use.  But
there's a lot of unwanted complexity behind the simple interface.
Switch to usb_create_simple().

Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/sh4/r2d.c

@@ -301,7 +301,7 @@ static void r2d_init(MachineState *machine)
                             "rtl8139", i==0 ? "2" : NULL);
 
     /* USB keyboard */
-    usbdevice_create("keyboard");
+    usb_create_simple(usb_bus_find(-1), "usb-kbd");
 
     /* Todo: register on board registers */
     memset(&boot_params, 0, sizeof(boot_params));