net/mlx5: optimize meter statistics

net/mlx5: optimize meter statistics

Meter statistics are each policer action each counter.
Totally 4 counters per each meter.
It causes cache missed
and lead to data forwarding performance low.

To optimize it, support pass counter for green
and drop counter for red.
Totally two counters per each meter.
Also use the global drop statistics for
all meter drop action.

Limitations as below:
1. It does not support yellow counter and return 0.
2. All the meter colors with drop action will be
   counted only by the global drop statistics.
3. Red color must be with drop action.

Signed-off-by: Li Zhang <lizh@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>