[baremetal] Add two interfaces to the opnfv vm

[baremetal] Add two interfaces to the opnfv vm

opnfv vm requires connectivity to two physical interfaces of the host.
These interfaces are:
 1 - admin, where DHCP requests will arrive from blades to do PXE boot
 2 - mgmt, which connects to the mgmt of the blades to do the ansible
   configuration

To achive this, it is required:
 1 - Two libvirt networks that connect to two different linux bridges.
   The important physical interfaces are connected to them. The
   interfaces name is fetched from the idf
 2 - Two templates representing the new libvirt networks
   (net-mgmt.xml.j2 and net-admin.xml.j2)
 3 - Two interfaces defined in vm.xml.j2

Change-Id: I9037aa36802cfde44717b9394bab79b22d7dfaab
Signed-off-by: Manuel Buil <mbuil@suse.com>