examples/vhost: support new VMDQ API for i40e

examples/vhost: support new VMDQ API for i40e

In Niantic, if VMDQ mode is set, all queues are allocated to VMDQ in DPDK.
In I40E, only configured part of continous queues are allocated to VMDQ.
The rte_eth_dev_info structure is extended to provide VMDQ queue base,
queue number, and VMDQ pool base information.
This patch support the new VMDQ API in vhost example.

FIXME in PMD:
 * added mac address will be flushed at rte_eth_dev_start.
 * we don't support selectively setting up queues well.

Test report: http://dpdk.org/ml/archives/dev/2014-December/009427.html

Signed-off-by: Huawei Xie <huawei.xie@intel.com>
Acked-by: Jing Chen <jing.d.chen@intel.com>
Tested-by: Jingguo Fu <jingguox.fu@intel.com>