mt76: mt7603: fix reading target tx power from eeprom

For the external PA (TSSI OFF) case, the target power needs to be read
from a different location in EEPROM
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7603/eeprom.h

@@ -69,6 +69,8 @@ enum mt7603_eeprom_field {
 
 	MT_EE_CP_FT_VERSION =			0x0f0,
 
+	MT_EE_TX_POWER_TSSI_OFF =		0x0f2,
+
 	MT_EE_XTAL_FREQ_OFFSET =		0x0f4,
 	MT_EE_XTAL_TRIM_2_COMP =		0x0f5,
 	MT_EE_XTAL_TRIM_3_COMP =		0x0f6,

drivers/net/wireless/mediatek/mt76/mt7603/init.c

@@ -465,9 +465,13 @@ mt7603_init_txpower(struct mt7603_dev *dev,
 	u8 *eeprom = (u8 *)dev->mt76.eeprom.data;
 	int target_power = eeprom[MT_EE_TX_POWER_0_START_2G + 2] & ~BIT(7);
 	u8 *rate_power = &eeprom[MT_EE_TX_POWER_CCK];
+	bool ext_pa = eeprom[MT_EE_NIC_CONF_0 + 1] & BIT(1);
 	int max_offset, cur_offset;
 	int i;
 
+	if (ext_pa && is_mt7603(dev))
+		target_power = eeprom[MT_EE_TX_POWER_TSSI_OFF] & ~BIT(7);
+
 	if (target_power & BIT(6))
 		target_power = -(target_power & GENMASK(5, 0));