Add scheduler support for PCI passthrough

PCI tracker updates the PCI stats information which provide an abstract
resource view to the scheduler

Openstack clients request PCI devices using PCI aliases, which are
converted to PCI requests. The PCI passthrough filter checks the PCI stats
for nodes that can satisfy the request of the instance, and gives the
schedule result.

bp:pci-passthrough-base

Change-Id: I0ede4caefab8b22126d0c8b9293f023aa4780e36
Signed-off-by: Yongli He <yongli.he@intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Merge "Add scheduler support for PCI passthrough"