mt76: mt7921: fix max aggregation subframes setting

The hardware can only handle 64 subframes in rx direction and 128 for tx.
Improves throughput with APs that can handle more than that

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210507100211.15709-2-nbd@nbd.name

drivers/net/wireless/mediatek/mt76/mt7921/init.c

@@ -76,8 +76,8 @@ mt7921_init_wiphy(struct ieee80211_hw *hw)
 	struct wiphy *wiphy = hw->wiphy;
 
 	hw->queues = 4;
-	hw->max_rx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF;
-	hw->max_tx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF;
+	hw->max_rx_aggregation_subframes = 64;
+	hw->max_tx_aggregation_subframes = 128;
 
 	hw->radiotap_timestamp.units_pos =
 		IEEE80211_RADIOTAP_TIMESTAMP_UNIT_US;