wifi: mt76: mt7996: fix wmm set of station interface to 3

According to connac3 HW design, the WMM index of AP and STA interface
should be 0 and 3, respectively.

Fixes: 98686cd2 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Link: https://patch.msgid.link/20240816094635.2391-3-shayne.chen@mediatek.com


Signed-off-by: Felix Fietkau <nbd@nbd.name>