asus-nb-wmi: add wapf=4 quirk for ASUS X75VD

Wi-Fi on ASUS X75VD laptop does not work unless asus_nb_wmi module
is loaded with wapf=4 option. Add quirk for this.

Signed-off-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>