Description of problem: Nova currently tracks PCI devices via the PCI manager. This has proven difficult to configure and even tougher to debug when misconfigured. We would benefit from moving some of the inventorying of PCI devices to placement. Not only would this allow us to remove the 'PciPassthroughFilter' but it would provide useful information to operators, who could simply query placement to get an understanding of PCI device inventory across a deployment. This RFE tracks the introduction of PCI devices to placement as child providers of the compute node.