ACPI / scan: Drop the second argument of acpi_device_unregister()

Drop the second argument of acpi_device_unregister(), type, which is
not used by that function.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>