tipc: Eliminate use of user registry by configuration service

Simplifies TIPC's configuration service so that it no longer registers
its port with the user registry, since the service doesn't take advantage
of any of the registry's capabilities.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>