net/mlx5e: Prepare for flow meter offload if hardware supports it

If flow meter aso object is supported, set the allocated range, and
initialize aso wqe.

The allocated range is indicated by log_meter_aso_granularity in HW
capabilities, and currently is 6.

Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Reviewed-by: Ariel Levkovich <lariel@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>