RPL dio handler update

Added neighbour add call for wi-sun for succesfully unicast DIS send operation.

Change-Id: I1de426da611c1ba0cf2275db37b05649921c188e

Author: Juha Heiskanen

source/RPL/rpl_control.c

@@ -977,6 +977,9 @@ static buffer_t *rpl_control_dio_handler(protocol_interface_info_entry_t *cur, r
     const rpl_dodag_conf_t *conf = rpl_dodag_get_config(dodag);
     if (!conf) {
         /* TODO - rate limit DIS? */
+        if (domain->new_parent_add && !domain->new_parent_add(buf->src_sa.address, domain->cb_handle)) {
+            goto invalid_parent;
+        }
         rpl_control_transmit_dis(domain, cur, RPL_SOLINFO_PRED_DODAGID | RPL_SOLINFO_PRED_INSTANCEID, instance_id, dodagid, 0, buf->src_sa.address);
         goto invalid_parent;
     }