We rename struct tipc_server to struct tipc_topsrv. This reflect its now
specialized role as topology server. Accoringly, we change or add function
prefixes to make it clearer which functionality those belong to.

There are no functional changes in this commit.
Acked-by: NYing.Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>