mt76: connac: update BA win size in Rx direction

Update BA size used data transimission in the Rx direction to improve Rx
throughput.

Reviewed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Leon Yen <leon.yen@mediatek.com>
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>