ACPI / PCI: Stub out pci_acpi_crs_quirks() and make it x86 specific

For pci_acpi_crs_quirks(), ia64 already doesn't use it, and we can
not foresee it should be used in ARM64, so stub out pci_acpi_crs_quirks()
to avoid introducing platform specific dummy stub function.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index d504613..ea6428b 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -96,7 +96,12 @@
 /* Arch-defined function to add a bus to the system */
 
 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root);
+
+#ifdef CONFIG_X86
 void pci_acpi_crs_quirks(void);
+#else
+static inline void pci_acpi_crs_quirks(void) { }
+#endif
 
 /* --------------------------------------------------------------------------
                                     Processor