coresight: etm3x: Rearrange cp14 access detection

As we are about to refactor the platform specific handling,
move the DT property handling to generic helpers.
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-etm3x.c

@@ -802,9 +802,9 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
 			return PTR_ERR(pdata);
 
 		adev->dev.platform_data = pdata;
-		drvdata->use_cp14 = of_property_read_bool(np, "arm,cp14");
 	}
 
+	drvdata->use_cp14 = fwnode_property_read_bool(dev->fwnode, "arm,cp14");
 	dev_set_drvdata(dev, drvdata);
 
 	/* Validity for the resource is already checked by the AMBA core */