It is possible to register _Qxx from namespace and use the ECDT EC to
perform event handling. The reported bug reveals that Windows is using ECDT
in this way in case the namespace EC is not present. This patch facilitates
Linux to support ECDT in this way.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=115021Reported-and-tested-by: Luya Tshimbalanga <luya@fedoraproject.org>
Tested-by: Jonh Henderson <jw.hendy@gmail.com>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>