i40e: Add a dummy packet template

The hardware requires a full packet template to be pointed to when adding
hardware flow filters.  This patch adds the template and uses it for
programming filters.

Change-ID: I09db9f4ab0207ca9c520ae36596d74e1a0663ae5
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>