ACPI: add config for BIOS table scan

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>
[Linux commit 8a1664be0b922dd6afd60eca96a992ef5ec22c40]
[Include <xen/kconfig.h> in osl.c so that it could use IS_ENABLED]
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Doug Goldstein <cardoe@cardoe.com>
Acked-by: Jan Beulich <jbeulich@suse.com>