tipc: eliminate configuration for maximum number of name subscriptions

Gets rid of the need for users to specify the maximum number of
name subscriptions supported by TIPC. TIPC now automatically provides
support for the maximum number of name subscriptions to 65535.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>