net/mlx5: change Direct Verbs counter to indexed

net/mlx5: change Direct Verbs counter to indexed

This part of the counter optimize change the DV counter to indexed as
what have already done in verbs. In this case, all the mlx5 flow counter
can be addressed by index.

The counter index is composed of pool index and the counter offset in
the pool counter array. The batch and none batch counter dcs ID offset
0x800000 is used to avoid the mix up for the index. As batch counter dcs
ID starts from 0x800000 and none batch counter dcs starts from 0, the
0x800000 offset is added to the batch counter index to indicate the
index of batch counter.

The counter pointer in rte_flow struct will be aligned to index instead
of pointer. It will save 4 bytes memory for every rte_flow. With
millions of rte_flow, it will save MBytes memory.

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