wifi: mt76: fix rate reporting / throughput regression on mt7915 and newer

mt7915 and newer need to report the rate_info that's stored in wcid->rate,
since they don't fill info->status.rates.

Cc: Jonas Jelonek <jelonek.jonas@gmail.com>
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Link: https://lore.kernel.org/all/CABXGCsP0znm9pS-MiKtyxTXR7XiyFVqen0qzNpicGHDZKCzbwg@mail.gmail.com/


Fixes: 44fa75f2 ("mac80211: extend current rate control tx status API")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220927093823.6007-1-nbd@nbd.name