ACPICA: Linux-specific header: Add support for s390x compilation

ACPICA commit ecac9504e32d3b501c8cb021afb253b4a83fc82f

Adds s390x as a 64-bit architecture.

Link: https://github.com/acpica/acpica/commit/ecac9504
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>