Previously, for tunnel packets, such as VXLAN/NVGRE, the vlan
tags of the inner header will be stripped without putting vlan
info to descriptor, what is not expected behaviour.
This patch fixes it by changing hardware configuration to leave
the inner packet alone.
Fixes: 4861cde46116 ("i40e: new poll mode driver")
Fixes: a778a1fa2e4e ("i40e: set up and initialize flow director")
Signed-off-by: Jingjing Wu <jingjing.wu@intel.com>