don't load asus-acpi if model is not supported

asus_hotk_get_info should return -ENODEV if the model is not supported.
http://bugzilla.kernel.org/show_bug.cgi?id=10389



Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>