ethdev: add packet mode in meter profile structure

ethdev: add packet mode in meter profile structure

Currently meter algorithms only supports rate is bytes per second (BPS).
Add packet_mode flag in meter profile parameters data structure.
So that it can meter traffic by packet per second.

When packet_mode is 0, the profile rates and bucket sizes are
specified in bytes per second and bytes
when packet_mode is not 0, the profile rates and bucket sizes are
specified in packets and packets per second.

The below structure will be extended:
rte_mtr_meter_profile
rte_mtr_capabilities

Signed-off-by: Li Zhang <lizh@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>