FIX: nfv_density

- use correct osi_layer=L2 (so L2 spoofing check is switched off
  in case of avf driver)
- add pci address information to eth interface in topology file
- nfv_density chain_ipsec tests work only with DPDK
  in current implementation

Change-Id: I233c6e5634a14581960c7459b87f11fcee8365bd
Signed-off-by: Jan Gelety <jgelety@cisco.com>