ACPI: remove __init/__exit from Asus .add()/.remove() methods

Even though the devices claimed by asus_acpi.c can not be hot-plugged, the
driver registration infrastructure allows the .add() and .remove() methods to
be called at any time while the driver is registered.  So remove __init and
__exit from them.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>