net/mlx5: manage shared counters in three-level table

net/mlx5: manage shared counters in three-level table

Currently, to check if any shared counter with same ID existing, it will
have to loop the counter pools to search for the counter. Even add the
counter to the list will also not so helpful while there are thousands
of shared counters in the list.

Change Three-Level table to look up the counter index saved in the
relevant table entry will be more efficient.

This patch introduces the Three-level table to save the ID relevant
counter index in the table. Then the next while the same ID comes, just
check the table entry of this ID will get the counter index directly.
No search will be needed.

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