mt76x2: fix WMM parameter configuration

Fix hw queue configuration since mt76x2 devices use a reverse queue
enumeration respect to mac80211 one:
 - 0: AC_BE
 - 1: AC_BK
 - 2: AC_VI
 - 3: AC_VO

The issue can be reproduced sending two concurrent flow using
two separate queues:
 - VO: 20Mbps UDP traffic
 - BE: TCP traffic

In this scenario the UDP traffic will be blocked by the TCP one.
Fix it configuring properly WMM hw queue parameters

Fixes: 7bc04215 ("mt76: add driver code for MT76x2e")
Tested-by: Gaetano Catalli <gaetano.catalli@gmail.com>
Signed-off-by: Gaetano Catalli <gaetano.catalli@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Acked-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>