net/mlx5e: Added 'raw_errors_laneX' fields to ethtool statistics

These are counters for errors received on rx side, such as
FEC errors.

Signed-off-by: Shay Agroskin <shayag@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>