virsh: nodedev: ability to filter CCW capabilities
    
    Now that the node_device driver is aware of CCW devices, let's hook up
    virsh so that we can filter them properly.
    
    Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
    Reviewed-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
    Signed-off-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>