When running on Xen, kudzu is kind enough to set up a login prompt on Xen's
"xvc" console. However, with F-9 pv_ops based kernel-xen, Xen's console will now
be available as "hvc", so e.g. this needs to be updated:

  hwconf.c:147:                            !strncmp(dev->device, "xvc", 3)));
  keyboard.c:327:                fd = open("/dev/xvc0", O_RDONLY);
  keyboard.c:336:                    kbddev->device = strdup("xvc0");

There is already hvc handling, bug only on ppc.

(Note, not assigning to kudzu owner until we switch rawhide over. Latest scratch
build available from here:

  http://koji.fedoraproject.org/koji/taskinfo?taskID=460974
)