TX rate limiting on VFs based on byte counts

[byteocean]

Performing TX rate limiting on VFs via sysfs parameters was not valid anymore #488. A suggested alternative approach by Nvidia is to use the ip command ip link set ens5f0np0 vf 0 max_tx_rate 10000 min_tx_rate 10000 to configure VF's max tx rate.

• verify if the suggested command works or not
• integrate the suggested approach into dpservice