MT_MIB_SDR36
mt76_rr(dev, MT_MIB_SDR36(0));
mt76_rr(dev, MT_MIB_SDR36(1));
tx_time = mt76_get_field(dev, MT_MIB_SDR36(idx),
mt76_rr(dev, MT_MIB_SDR36(0));
tx_time = mt76_get_field(dev, MT_MIB_SDR36(idx),