ACPI: add config for BIOS table scan

With the addition of ARM64 that does not have a traditional BIOS to
scan, add a config option which is selected on x86 (ia64 doesn't need
it either, it is EFI/UEFI based system) to do the traditional BIOS
scanning for tables.

Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d24887b..5617750 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -132,6 +132,7 @@
 	select GENERIC_CPU_AUTOPROBE
 	select HAVE_ARCH_AUDITSYSCALL
 	select ARCH_SUPPORTS_ATOMIC_RMW
+	select ACPI_LEGACY_TABLES_LOOKUP if ACPI
 
 config INSTRUCTION_DECODER
 	def_bool y