vfio: add multi container support

vfio: add multi container support

This patch adds APIs to support container create/destroy and device
bind/unbind with a container. It also provides API for IOMMU programing
on a specified container.

A driver could use "rte_vfio_container_create" helper to create a new
container from eal, use "rte_vfio_container_group_bind" to bind a device
to the newly created container. During rte_vfio_setup_device the container
bound with the device will be used for IOMMU setup.

Signed-off-by: Junjie Chen <junjie.j.chen@intel.com>
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>