i40e: Fix byte ordering in ARP NS code for X722

This patch fixes byte ordering problems found when enabling this feature
support. Without this patch, the feature will not work correctly. This
patch fixes the definitions to have the correct byte order.

Change-ID: Ic7489fbcbe2195df7be62ff5e359201b827cefe6
Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>