net/mlx4_en: Align tx path structures to cache lines
Reorganize struct mlx4_en_tx_ring to have:
- One cache line containing last_nr_txbb & cons & wake_queue, used by tx
completion.
- One cache line containing fields dirtied by mlx4_en_xmit()
- Following part is read mostly and shared by cpus.
Align struct mlx4_en_tx_info to a cache line
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Amir Vadai <amirv@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>