NSM: Move NSM program and procedure numbers to fs/lockd/mon.c

Clean up: Move the RPC program and procedure numbers for NSM into the
one source file that needs them: fs/lockd/mon.c.

And, as with NLM, NFS, and rpcbind calls, use NSMPROC_FOO instead of
SM_FOO for NSM procedure numbers.

Finally, make a couple of comments more precise: what is referred to
here as SM_NOTIFY is really the NLM (lockd) NLMPROC_SM_NOTIFY downcall,
not NSMPROC_NOTIFY.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>