vfio not recognized if compiled into kernel

[choppsv1]

Newer ubuntu distributions have kernels with vfio compiled in (i.e., it is not present as a module). dpdk_* scripts are looking for the module and failing if not found. trex also fails to work unless I modify the dpdk_nic_bind script to not fail and instead assume vfio, and then pre-bind the interface to vfio before running trex.

[hhaim]

@choppsv1 thanks. We will look into this