Update MCU command usage to fix WoW configuration with disconnection
and bitmap pattern and to avoid magic number.

Fixes: ffa1bf97 ("mt76: mt7921: introduce PM support")
Reviewed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: YN Chen <yn.chen@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>