DPDK: Support vRouter over VF interface
DPDK: Support vRouter over VF interface

This adds support for creating setups, where the DPDK vRouter is bound to PCI
virtual function instead of to the physical interface.

Change-Id: I6b2354831056c87a72a52b37342ea599305e6165
Closes-Bug: #1564935

Juniper/contrail-fabric-utils,Juniper/contrail-fabric-utils