Wake on WLAN(wowlan) is a feature which allows devices
to be woken up from suspend state through wlan events.

When user enables wowlan feature and then let the device
enter suspend state, wowlan firmware will be loaded by
the driver and periodically monitors wifi packets.
Power consumption of wifi chip will be reduced in this
state.

If wowlan firmware detects that specific wlan event
happens, it will issue wakeup signal to trigger resume
process. Driver will load normal firmware and let wifi
chip return to the original state.

Currently supported wlan events include receiving magic packet,
rekey packet and deauth packet, and disconnecting from AP.
Signed-off-by: Chin-Yen Lee <timlee@realtek.com>
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>