net: change netdev->features to u32

Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.

Occurences found by `grep -r` on net/, drivers/net, include/

[ Move features and vlan_features next to each other in
  struct netdev, as per Eric Dumazet's suggestion -DaveM ]

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index b100bd5..55786a0 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1142,7 +1142,7 @@
  * privs required. */
 static int set_offload(struct net_device *dev, unsigned long arg)
 {
-	unsigned int old_features, features;
+	u32 old_features, features;
 
 	old_features = dev->features;
 	/* Unset features, set them as we chew on the arg. */