[IPV4]: Convert IPv4 devconf to an array

This patch converts the ipv4_devconf config members (everything except
sysctl) to an array.  This allows easier manipulation which will be
needed later on to provide better management of default config values.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/infiniband/hw/amso1100/c2.c b/drivers/infiniband/hw/amso1100/c2.c
index 58bc272..0aecea6 100644
--- a/drivers/infiniband/hw/amso1100/c2.c
+++ b/drivers/infiniband/hw/amso1100/c2.c
@@ -672,7 +672,7 @@
 	 * rdma interface.
 	 */
 	in_dev = in_dev_get(netdev);
-	in_dev->cnf.arp_ignore = 1;
+	IN_DEV_CONF_SET(in_dev, ARP_IGNORE, 1);
 	in_dev_put(in_dev);
 
 	return 0;