This adds "bit" property type, which is a boolean stored in a 32 bit
integer field, with legal values on and off.  Will be used by virtio for
feature bits.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>