We don't allow to modify it after realization. So we can simply turn
it into a static property.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180619134141.29478-10-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>