For some testing, it an be usefull to have more physical
NICS that DPDK's PMDs can bind to.
Example to run vpp within a VM with 3 emulated NICs:
export VPP_VAGRANT_NICS=3
vagrant up
Change-Id: I82d70f21c0a9ceba126ab6620c3b869d590d8de1
Signed-off-by: Vincent JARDIN <vincent.jardin@6wind.com>