ACPI / tables: move arch-specific symbol to asm/acpi.h

The constant that defines max phys address where the new upgraded
ACPI table should be allocated is arch-specific.  Move it to
<asm/acpi.h>

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>