mt76: connac: fix sta_rec_wtbl tag len

Similar to mt7915 driver, fix tag len error for sta_rec_wtbl, which
causes fw parsing error for the tags placed behind it.

Fixes: d0e274af ("mt76: mt76_connac: create mcu library")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>