Finish the i40e implementation of get_settings for ethtool.

Change-ID: Iec81835aa9380723ae9288bcb79b30a6a1ecd498
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>