ACPI: glue: Drop cleanup callback from struct acpi_bus_type

Since PCI was the only user of the ->cleanup callback in struct
acpi_bus_type and it is not using struct acpi_bus_type any more,
drop that callback from there and update acpi_device_notify_remove()
accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Ferry Toth <fntoth@gmail.com>