tipc: make cluster size threshold for monitoring configurable

In this commit, we introduce support to configure the minimum
threshold to activate the new link monitoring algorithm.

Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/netlink.h b/net/tipc/netlink.h
index ed1dbcb..4ba0ad4 100644
--- a/net/tipc/netlink.h
+++ b/net/tipc/netlink.h
@@ -55,6 +55,7 @@
 extern const struct nla_policy tipc_nl_bearer_policy[];
 extern const struct nla_policy tipc_nl_media_policy[];
 extern const struct nla_policy tipc_nl_udp_policy[];
+extern const struct nla_policy tipc_nl_monitor_policy[];
 
 int tipc_netlink_start(void);
 int tipc_netlink_compat_start(void);