asus-laptop: fix wapf, wlan_status and bluetooth_status module_param permissions

The wapf module parameters defines the behavior of the Fn+Fx wlan key.
The wlan_status and bluetooth_status module parameters are for setting the
wlan/bluetooth status on boot.

All above module parameters are determinated only at the module load time.
 Change the value after the module is loaded does not make sense and has
no effect at all, thus set the permissions to 0444 instead of 0644.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>