e1000: advertise transmit time stamping

This driver now offers software transmit time stamping, so it should
advertise that fact via ethtool. Compile tested only.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>

Cc: Willem de Bruijn <willemb@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: e1000-devel@lists.sourceforge.net
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/e1000/e1000_ethtool.c

@@ -1851,6 +1851,7 @@ static const struct ethtool_ops e1000_ethtool_ops = {
 	.get_sset_count         = e1000_get_sset_count,
 	.get_coalesce           = e1000_get_coalesce,
 	.set_coalesce           = e1000_set_coalesce,
+	.get_ts_info		= ethtool_op_get_ts_info,
 };
 
 void e1000_set_ethtool_ops(struct net_device *netdev)