powerpc/eeh: Bug fix and enhancement

This patch set contains three patches, all to eeh.c, which fix a issue seen on PCIe adapters with devices below PCIe bridge/switch, gracefully handle case where driver sets 'needs_freset' for non-PCIe adapter, and display location information for both PCIe bus and device for the device which detected an error.

Patches were tested on P5/P6/P7 platforms on a variety of PCI, PCI-X and PCI-E adapters with no regressions.