Add capability to inform VF's about PF link status change

[azelezniak]

Looks like dpdk-16.11 missing ping_vfs function for Niantic (17.02 has it for i40e)
also parameter have to be passed from configuration file to control VF notification

[krjoshi]

DPDK bug. Patch submitted for inclusion in 1705

[ScottDaniels]

Patch is here: http://dpdk.org/dev/patchwork/patch/22090/