For the upcoming `socket` affinity, PCI stats needs to know the
host's NUMA topology in order to calculate the socket affinity of PCI
devices (based on their 'numa_node'). In this patch, the PCI manager
starts using its compute_node parameter to give a NUMA topology to PCI
stats.
PCI stats needs to track the NUMA topology at the object (not the
class) level, so all the '_filter_*()' classmethods that, in a
subsequent patch, will either use 'self.numa_topology' directly or
call a method that does, are moved to the object level. They were only
ever called via self anyways.
Implements: blueprint pci-socket-affinity
Change-Id: I1d270cc3e88a74097eefe3b887106222ae06fe1c
890b6d54a6