net/mlx5: optimize hash list synchronization

net/mlx5: optimize hash list synchronization

Since all the hash table operations are related with one dedicated
bucket, the hash table lock and gen_cnt can be allocated per-bucket.

Currently, the hash table uses one global lock to protect all the
buckets, that global lock avoids the buckets to be operated at one
time, it hurts the hash table performance. And the gen_cnt updated
by the entire hash table causes incorrect redundant list research.

This commit optimized the lock and gen_cnt to bucket solid allows
different bucket entries can be operated more efficiently.

Signed-off-by: Suanming Mou <suanmingm@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>