[RTNETLINK]: Link creation API

Add rtnetlink API for creating, changing and deleting software devices.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 94cc77c..e7913ee 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -540,6 +540,9 @@
 	struct device		dev;
 	/* space for optional statistics and wireless sysfs groups */
 	struct attribute_group  *sysfs_groups[3];
+
+	/* rtnetlink link ops */
+	const struct rtnl_link_ops *rtnl_link_ops;
 };
 #define to_net_dev(d) container_of(d, struct net_device, dev)