ACPI / EC: Refine event/query debugging messages.

This patch refines event/query debugging messages to use a unified format
as commands. Developers can clearly find different processes by checking
different log seperators. No functional changes.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>