i40e: Add new update VSI flow to accommodate FW fix with VSI Loopback mode

All VSIs on a VEB should either have loopback enabled or disabled, a
mixed mode is not supported for a VEB. Since our driver supports multiple
VSIs per PF that need to talk to each other make sure to enable Loopback
for the PF and FDIR VSI as well.

Also, we now have to explicitly enable Loopback mode otherwise we fail
VSI creation for VMDq and VF VSIs.

Change-ID: Ib68c3ea4aeb730ac9468f930610de456efbe5b20
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>