fs_enet: enable transmit time stamping.

This patch enables software (and phy device) transmit time stamping.
Compile tested only.

Cc: Pantelis Antoniou <pantelis.antoniou@gmail.com>
Cc: Vitaly Bordug <vbordug@ru.mvista.com>
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/fs_enet/fs_enet-main.c

@@ -697,6 +697,8 @@ static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		sc |= BD_ENET_TX_PAD;
 	CBDS_SC(bdp, sc);
 
+	skb_tx_timestamp(skb);
+
 	(*fep->ops->tx_kickstart)(dev);
 
 	spin_unlock_irqrestore(&fep->tx_lock, flags);