Additional stubs:
 - chr_baum_init
 - qemu_chr_open_spice_vmc
 - qemu_chr_open_spice_port
Signed-off-by: NNikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>