net/mlx5e: Move common case counters within sq_stats struct

For data cache locality considerations, we moved the nop and
csum_offload_inner within sq_stats struct as they are more
commonly accessed in xmit path.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>