mt76: mt7915: fix tssi indication field of DBDC NICs

Correct the bitfield which indicates TSSI on/off for MT7915D NIC.
Signed-off-by: Evelyn Tsai <evelyn.tsai@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7915/eeprom.h

@@ -99,12 +99,15 @@ static inline bool
 mt7915_tssi_enabled(struct mt7915_dev *dev, enum nl80211_band band)
 {
 	u8 *eep = dev->mt76.eeprom.data;
+	u8 val = eep[MT_EE_WIFI_CONF + 7];
 
-	/* TODO: DBDC */
-	if (band == NL80211_BAND_5GHZ)
-		return eep[MT_EE_WIFI_CONF + 7] & MT_EE_WIFI_CONF7_TSSI0_5G;
+	if (band == NL80211_BAND_2GHZ)
+		return val & MT_EE_WIFI_CONF7_TSSI0_2G;
+
+	if (dev->dbdc_support)
+		return val & MT_EE_WIFI_CONF7_TSSI1_5G;
 	else
-		return eep[MT_EE_WIFI_CONF + 7] & MT_EE_WIFI_CONF7_TSSI0_2G;
+		return val & MT_EE_WIFI_CONF7_TSSI0_5G;
 }
 
 extern const u8 mt7915_sku_group_len[MAX_SKU_RATE_GROUP_NUM];