net/mlx5: DR, Remove icm_addr from mlx5dr_icm_chunk to reduce memory

It can be calculated quickly from buddy memory pool by
function mlx5dr_icm_pool_get_chunk_icm_addr().
This function is very lightweight and straightforward.

Reduce 8 bytes and current size of struct mlx5_dr_icm_chunk
is 64 bytes.

Signed-off-by: Rongwei Liu <rongweil@nvidia.com>
Reviewed-by: Shun Hao <shunh@nvidia.com>
Reviewed-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>