There is no keyboard support currently in libvirt.

For some platforms (PPC64 QEMU) this makes graphics unusable,
since the keyboard is not implicit and it can't be added via libvirt.
Signed-off-by: NLi Zhang <zhlcindy@linux.vnet.ibm.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>