mt76: mt7603: disable merge of OTP ROM data by default

The reference driver does not seem to enable it by default, only under certain
conditions, e.g. when a .bin file is loaded.
Make it opt-in via a device tree property for now, in case it is needed on some
boards.
Signed-off-by: Felix Fietkau <nbd@nbd.name>

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

 // SPDX-License-Identifier: ISC
 
+#include <linux/of.h>
 #include "mt7603.h"
 #include "eeprom.h"
 
@@ -100,10 +101,14 @@ mt7603_apply_cal_free_data(struct mt7603_dev *dev, u8 *efuse)
 		MT_EE_TX_POWER_1_START_2G,
 		MT_EE_TX_POWER_1_START_2G + 1,
 	};
+	struct device_node *np = dev->mt76.dev->of_node;
 	u8 *eeprom = dev->mt76.eeprom.data;
 	int n = ARRAY_SIZE(cal_free_bytes);
 	int i;
 
+	if (!np || !of_property_read_bool(np, "mediatek,eeprom-merge-otp"))
+		return;
+
 	if (!mt7603_has_cal_free_data(dev, efuse))
 		return;