Fix wrong reserved bits offsets.

Fixes: 97b5484e ("net/mlx5: Add HW bits and definitions required for SW steering")
Signed-off-by: Yevgeny Kliteynik <kliteyn@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>