team: add support for sending multicast rejoins

Similar to what is implemented in bonding. User is able to ask team
driver to send IGMP rejoins in case port is enabled or disabled. Using
previously introduced netdev notifier.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index b0b8368..a899dc2 100644
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -200,6 +200,12 @@
 		atomic_t count_pending;
 		struct delayed_work dw;
 	} notify_peers;
+	struct {
+		unsigned int count;
+		unsigned int interval; /* in ms */
+		atomic_t count_pending;
+		struct delayed_work dw;
+	} mcast_rejoin;
 	long mode_priv[TEAM_MODE_PRIV_LONGS];
 };