mt76: mt7921: enlarge maximum VHT MPDU length to 11454

Enlarge maximum MPDU length to 11454 that both mt7921/mt7922 can support.
After this fixing, we can get better performance.

Fixes: 5c14a5f9 ("mt76: mt7921: introduce mt7921e support")
Tested-by: Ming Yen Hsieh <mingyen.hsieh@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

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

@@ -306,7 +306,7 @@ int mt7921_register_device(struct mt7921_dev *dev)
 			IEEE80211_HT_CAP_LDPC_CODING |
 			IEEE80211_HT_CAP_MAX_AMSDU;
 	dev->mphy.sband_5g.sband.vht_cap.cap |=
-			IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_7991 |
+			IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454 |
 			IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK |
 			IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE |
 			IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE |