ospf6d: add support for route tags

[ported by Paul Jakma, paul@jakma.org]
diff --git a/ospf6d/ospf6_asbr.h b/ospf6d/ospf6_asbr.h
index f3df90b..14113b0 100644
--- a/ospf6d/ospf6_asbr.h
+++ b/ospf6d/ospf6_asbr.h
@@ -47,7 +47,8 @@
   u_int32_t id;
 
   struct in6_addr forwarding;
-  /* u_int32_t tag; */
+
+  route_tag_t tag;
 
   ifindex_t ifindex;
 };
@@ -82,7 +83,8 @@
 extern void ospf6_asbr_redistribute_add (int type, ifindex_t ifindex,
                                          struct prefix *prefix,
                                          u_int nexthop_num,
-                                         struct in6_addr *nexthop);
+                                         struct in6_addr *nexthop,
+                                         route_tag_t tag);
 extern void ospf6_asbr_redistribute_remove (int type, ifindex_t ifindex,
                                             struct prefix *prefix);