iio: adc: rcar-gyroadc: Use of_device_get_match_data() helper

Use the of_device_get_match_data() helper instead of open coding.
Note that the rcar-gyroadc driver is used with DT only, so there's
always a valid match.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/rcar-gyroadc.c

@@ -487,8 +487,6 @@ static int rcar_gyroadc_init_supplies(struct iio_dev *indio_dev)
 
 static int rcar_gyroadc_probe(struct platform_device *pdev)
 {
-	const struct of_device_id *of_id =
-		of_match_device(rcar_gyroadc_match, &pdev->dev);
 	struct device *dev = &pdev->dev;
 	struct rcar_gyroadc *priv;
 	struct iio_dev *indio_dev;
@@ -525,7 +523,8 @@ static int rcar_gyroadc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	priv->model = (enum rcar_gyroadc_model)of_id->data;
+	priv->model = (enum rcar_gyroadc_model)
+		of_device_get_match_data(&pdev->dev);
 
 	platform_set_drvdata(pdev, indio_dev);