netdev: add HAVE_NET_DEVICE_OPS

As a concession to vendors who have to deal with one source for different
kernel versions, add a HAVE_NET_DEVICE_OPS so they don't end up hard
coding ifdef against kernel version.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 6095af5..76a89f8 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -545,6 +545,7 @@
  *
  * void (*ndo_poll_controller)(struct net_device *dev);
  */
+#define HAVE_NET_DEVICE_OPS
 struct net_device_ops {
 	int			(*ndo_init)(struct net_device *dev);
 	void			(*ndo_uninit)(struct net_device *dev);