forcedeth: 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 <[e-mail]>

Cc: Willem de Bruijn <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/nvidia/forcedeth.c

···
 	.get_ethtool_stats = nv_get_ethtool_stats,
 	.get_sset_count = nv_get_sset_count,
 	.self_test = nv_self_test,
+	.get_ts_info = ethtool_op_get_ts_info,
 };
 
 /* The mgmt unit and driver use a semaphore to access the phy during init */