ACPICA: Add EXPORT_SYMBOL macros for install/remove SCI handler interfaces.

These recently added interfaces did not have these macros, used
by some hosts.

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>