PCI devices resource tracker

PCI device need to be scheduled according the resource status. The PCI
tracker provoides central contorl of the PCI resouces.

Discovered PCI devices are passed to the PCI tracker to track their status,
and to provide functions for compute node components to update, check, claim
the PCI devices resources.

PCI Tracker also updates PCI stats which provide infomation to the scheduler.

bp:pci-passthrough-base

Change-Id: Ia80633b5a52b88fd7c9aea168644283b00be0b49
Signed-off-by: Yongli He <yongli.he@intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Merge "PCI devices resource tracker"