To allow transport capabilities to be loaded dynamically, provide an API
for registering and unregistering the transports with the RPC client.
Eventually xprt_create_transport() will be changed to search the list of
registered transports when initializing a fresh transport.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTom Talpey <tmt@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>