Notify the need for overriding the default driver for Mellanox NIC
Notify the need for overriding the default driver for Mellanox NIC

In case of mellanox cards, the interfaces used for DPDK ports
shall not be bound with vfio-pci (default) driver. An explicit error
message shall be thrown when the required drivers are not specified
in the user templates.

Change-Id: I69b362079905c3957504e4958abfeeb9923cf07f

openstack/os-net-config