net: allow user to change NETIF_F_HIGHDMA

NETIF_F_HIGHDMA is like any other TX offloads, so allow user to toggle it.
This is needed later for bridge and bonding convertsion to hw_features.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -1080,7 +1080,7 @@ struct net_device {
 
 	/* Features valid for ethtool to change */
 	/* = all defined minus driver/device-class-related */
-#define NETIF_F_NEVER_CHANGE	(NETIF_F_HIGHDMA | NETIF_F_VLAN_CHALLENGED | \
+#define NETIF_F_NEVER_CHANGE	(NETIF_F_VLAN_CHALLENGED | \
 				  NETIF_F_LLTX | NETIF_F_NETNS_LOCAL)
 #define NETIF_F_ETHTOOL_BITS	(0x7f3fffff & ~NETIF_F_NEVER_CHANGE)
 
@@ -1098,6 +1098,7 @@ struct net_device {
 
 #define NETIF_F_ALL_TX_OFFLOADS	(NETIF_F_ALL_CSUM | NETIF_F_SG | \
 				 NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \
+				 NETIF_F_HIGHDMA | \
 				 NETIF_F_SCTP_CSUM | NETIF_F_FCOE_CRC)
 
 	/*