Update to support the newest virtif hypervisor interface:
Update to support the newest virtif hypervisor interface:

- Don't currently report any capabilities.
- Accept checksum related metadata, but don't do anything with it.
- Respect the new expectations of VIF_MBUF_EXTALLOC (from pooka@).

jqyy/drv-netif-dpdk,jqyy/drv-netif-dpdk