asus-wmi: Add quirk_no_rfkill_wapf4 for the Asus X456UF

The Asus X456UF has an airplane-mode indicator LED and the WMI WLAN user
bit set, so asus-wmi uses ASUS_WMI_DEVID_WLAN_LED (0x00010002) to store
the wlan state, which has a side-effect of driving the airplane mode
indicator LED in an inverted fashion.

quirk_no_rfkill prevents asus-wmi from registering RFKill switches at
all for this laptop and allows asus-wireless to drive the LED through
the ASHS ACPI device.  This laptop already has a quirk for setting
WAPF=4, so this commit creates a new quirk, quirk_no_rfkill_wapf4, which
both disables rfkill and sets WAPF=4.

Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
Reported-by: Carlo Caione <carlo@endlessm.com>
Reviewed-by: Corentin Chary <corentin.chary@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>