linux-phytec-ti

igc: Add ethtool support

This patch adds basic ethtool support to the device to allow
for configuration.

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>