net/mlx5: DR, Remove num_of_entries byte_size from struct mlx5_dr_icm_chunk

Target to reduce the memory consumption in large scale of flow rules.

They can be calculated quickly from buddy memory pool.
1. num_of_entries calls dr_icm_pool_get_chunk_num_of_entries().
2. byte_size calls dr_icm_pool_get_chunk_byte_size().

Use chunk size in dr_icm_chunk to speed up and the one in dr_ste_htbl
will be removed in the upcoming commit.

This commit reduce 8 bytes from struct mlx5_dr_icm_chunk and its
current size is 56 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>