NFSv4.1/pnfs: fix NFS with TLS in pnfs

Currently, even though xprtsec=tls is specified and used for operations
to MDS, any operations that go to DS travel over unencrypted connection.
Or additionally, if more than 1 DS can serve the data, then trunked
connections are also done unencrypted.

IN GETDEVINCEINFO, we get an entry for the DS which carries a protocol
type (which is TCP), then nfs4_set_ds_client() gets called with TCP
instead of TCP with TLS.

Currently, each trunked connection is created and uses clp->cl_hostname
value which if TLS is used would get passed up in the handshake upcall,
but instead we need to pass in the appropriate trunked address value.

Fixes: c8407f2e ("NFS: Add an "xprtsec=" NFS mount option")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>