mt76: mt7615: set spatial extension index

The vendor driver sets this in firmware rate control (which we don't use)
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7615/mac.c

@@ -639,7 +639,8 @@ int mt7615_mac_write_txwi(struct mt7615_dev *dev, __le32 *txwi,
 		txwi[3] |= cpu_to_le32(MT_TXD3_NO_ACK);
 
 	txwi[7] = FIELD_PREP(MT_TXD7_TYPE, fc_type) |
-		  FIELD_PREP(MT_TXD7_SUB_TYPE, fc_stype);
+		  FIELD_PREP(MT_TXD7_SUB_TYPE, fc_stype) |
+		  FIELD_PREP(MT_TXD7_SPE_IDX, 0x18);
 	if (is_usb)
 		txwi[8] = FIELD_PREP(MT_TXD8_L_TYPE, fc_type) |
 			  FIELD_PREP(MT_TXD8_L_SUB_TYPE, fc_stype);

drivers/net/wireless/mediatek/mt76/mt7615/mcu.c

@@ -887,6 +887,7 @@ mt7615_mcu_wtbl_generic_tlv(struct sk_buff *skb, struct ieee80211_vif *vif,
 	struct mt7615_vif *mvif = (struct mt7615_vif *)vif->drv_priv;
 	struct wtbl_generic *generic;
 	struct wtbl_rx *rx;
+	struct wtbl_spe *spe;
 	struct tlv *tlv;
 
 	tlv = mt7615_mcu_add_nested_tlv(skb, WTBL_GENERIC, sizeof(*generic),
@@ -914,6 +915,11 @@ mt7615_mcu_wtbl_generic_tlv(struct sk_buff *skb, struct ieee80211_vif *vif,
 	rx->rca1 = sta ? vif->type != NL80211_IFTYPE_AP : 1;
 	rx->rca2 = 1;
 	rx->rv = 1;
+
+	tlv = mt7615_mcu_add_nested_tlv(skb, WTBL_SPE, sizeof(*spe),
+					wtbl_tlv, sta_wtbl);
+	spe = (struct wtbl_spe *)tlv;
+	spe->spe_idx = 24;
 }
 
 static void