igc: Extend the ethtool supporting

Add show and configure network flow classification (NFC) methods
to the ethtool. Show the specifies Rx ntuple filters.
Configures receive network flow classification option or rules.

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>