wifi: mt76: fix 5 GHz connection regression on mt76x0/mt76x2

Some users have reported being unable to connect to MT76x0 APs running mt76
after a commit enabling the VHT extneded NSS BW feature.
Fix this regression by ensuring that this feature only gets enabled on drivers
that support it

Cc: stable@vger.kernel.org
Fixes: d9fcfc1 ("mt76: enable the VHT extended NSS BW feature")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220907095228.82072-1-nbd@nbd.name

drivers/net/wireless/mediatek/mt76/mac80211.c

@@ -267,7 +267,8 @@ static void mt76_init_stream_cap(struct mt76_phy *phy,
 	}
 	vht_cap->vht_mcs.rx_mcs_map = cpu_to_le16(mcs_map);
 	vht_cap->vht_mcs.tx_mcs_map = cpu_to_le16(mcs_map);
-	vht_cap->vht_mcs.tx_highest |=
+	if (ieee80211_hw_check(phy->hw, SUPPORTS_VHT_EXT_NSS_BW))
+		vht_cap->vht_mcs.tx_highest |=
 				cpu_to_le16(IEEE80211_VHT_EXT_NSS_BW_CAPABLE);
 }