acpi: use acpi_event_handler instead of interrupt_handler.
acpi: create fake acpi devices for FADT power and sleep buttons.

* adjust ACPIDeviceModule to accept nodes without ACPI_DEVICE_PATH_ITEM.
acpi_button: switch to fixed event and notify handlers.

* install a fixed event or notify handler depending on the device type.
* on handling, a non zero status is available for read.
* fixed #10154.