ACPI: kill acpi_get_physical_pci_device()

acpi_get_pci_dev() is (hopefully) better, and all callers have been
converted, so let's get rid of this duplicated functionality.

Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>