mt76: mt7915: fix he_mcs capabilities for 160mhz

At 160, this chip can only do 2x2 NSS.  Fix the features
accordingly, verified it shows up properly in iw phy foo info
now.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7915/init.c

@@ -646,12 +646,19 @@ mt7915_init_he_caps(struct mt7915_phy *phy, enum nl80211_band band,
 {
 	int i, idx = 0, nss = hweight8(phy->mt76->chainmask);
 	u16 mcs_map = 0;
+	u16 mcs_map_160 = 0;
 
 	for (i = 0; i < 8; i++) {
 		if (i < nss)
 			mcs_map |= (IEEE80211_HE_MCS_SUPPORT_0_11 << (i * 2));
 		else
 			mcs_map |= (IEEE80211_HE_MCS_NOT_SUPPORTED << (i * 2));
+
+		/* Can do 1/2 of NSS streams in 160Mhz mode. */
+		if (i < nss / 2)
+			mcs_map_160 |= (IEEE80211_HE_MCS_SUPPORT_0_11 << (i * 2));
+		else
+			mcs_map_160 |= (IEEE80211_HE_MCS_NOT_SUPPORTED << (i * 2));
 	}
 
 	for (i = 0; i < NUM_NL80211_IFTYPES; i++) {
@@ -753,10 +760,10 @@ mt7915_init_he_caps(struct mt7915_phy *phy, enum nl80211_band band,
 
 		he_mcs->rx_mcs_80 = cpu_to_le16(mcs_map);
 		he_mcs->tx_mcs_80 = cpu_to_le16(mcs_map);
-		he_mcs->rx_mcs_160 = cpu_to_le16(mcs_map);
-		he_mcs->tx_mcs_160 = cpu_to_le16(mcs_map);
-		he_mcs->rx_mcs_80p80 = cpu_to_le16(mcs_map);
-		he_mcs->tx_mcs_80p80 = cpu_to_le16(mcs_map);
+		he_mcs->rx_mcs_160 = cpu_to_le16(mcs_map_160);
+		he_mcs->tx_mcs_160 = cpu_to_le16(mcs_map_160);
+		he_mcs->rx_mcs_80p80 = cpu_to_le16(mcs_map_160);
+		he_mcs->tx_mcs_80p80 = cpu_to_le16(mcs_map_160);
 
 		mt7915_set_stream_he_txbf_caps(he_cap, i, nss);