mt76: move beacon_mask in mt76_dev

Move beacon_mask in mt76_dev data structure since it is used by
all drivers

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt76.h

@@ -470,6 +470,7 @@ struct mt76_dev {
 	u16 chainmask;
 
 	int beacon_int;
+	u8 beacon_mask;
 
 	struct mt76_sband sband_2g;
 	struct mt76_sband sband_5g;