For Notify operators, displays a comment that describe the meaning
of the notify value.

This patch updates the debugging information that is enabled for
CONFIG_ACPI_DEBUG builds.
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>