x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation

Use common ACPI resource discovery interfaces to simplify PCI host bridge
resource enumeration.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>