ACPI: pci_root: remove unused dev/fn information

We never use the PCI device & function number, so remove it to make
it clear that it's not needed.  Many PCI host bridges don't even
appear in config space, so it's meaningless to look at stuff from
_ADR, which doesn't exist in that case.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>