[NET]: Move hardware header operations out of netdevice.

Since hardware header operations are part of the protocol class
not the device instance, make them into a separate object and
save memory.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wan/lmc/lmc_proto.c b/drivers/net/wan/lmc/lmc_proto.c
index 31e17995..426c067 100644
--- a/drivers/net/wan/lmc/lmc_proto.c
+++ b/drivers/net/wan/lmc/lmc_proto.c
@@ -111,7 +111,7 @@
              * They set a few basics because they don't use sync_ppp
              */
             dev->flags |= IFF_POINTOPOINT;
-            dev->hard_header = NULL;
+
             dev->hard_header_len = 0;
             dev->addr_len = 0;
         }