wifi: mt76: mt7996: fix integer handling issue of mt7996_rf_regval_set()

This code is supposed to set a u32 value, but casting will not work on
big endian systems.
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1527816 ("Integer handling issues")
Fixes: 98686cd2 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7996/debugfs.c

@@ -653,8 +653,9 @@ static int
 mt7996_rf_regval_set(void *data, u64 val)
 {
 	struct mt7996_dev *dev = data;
+	u32 val32 = val;
 
-	return mt7996_mcu_rf_regval(dev, dev->mt76.debugfs_reg, (u32 *)&val, true);
+	return mt7996_mcu_rf_regval(dev, dev->mt76.debugfs_reg, &val32, true);
 }
 
 DEFINE_DEBUGFS_ATTRIBUTE(fops_rf_regval, mt7996_rf_regval_get,