asus-nb-wmi: Add wapf4 quirk for the X550VB

asus-nb-wmi: Add wapf4 quirk for the X550VB

commit 4ec7a45b51a32ee513898e2f1e42bb681b340fcf upstream.

X550VB as many others Asus laptops need wapf4 quirk to make RFKILL
switch be functional. Otherwise system boots with wireless card
disabled and is only possible to enable it by suspend/resume.

Bug report:
http://bugzilla.redhat.com/show_bug.cgi?id=1089731#c23

Reported-and-tested-by: Vratislav Podzimek <vpodzime@redhat.com>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>