bonding: add num_grat_arp attribute netlink support

Add IFLA_BOND_NUM_PEER_NOTIF to allow get/set of bonding parameter
num_grat_arp via netlink.  Bonding parameter num_unsol_na is
synonymous with num_grat_arp, so add only one netlink attribute
to represent both bonding parameters.

Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index 1ed7dff..01a9669 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -576,3 +576,9 @@
 
 	return 0;
 }
+
+int bond_option_num_peer_notif_set(struct bonding *bond, int num_peer_notif)
+{
+	bond->params.num_peer_notif = num_peer_notif;
+	return 0;
+}