iio:adc:rcar: Suppress clang W=1 warning about pointer to enum conversion.

Cast to a uintptr_t rather than directly to the enum.

As per the discussion in below linked media patch.

Link: https://lore.kernel.org/linux-media/CAK8P3a2ez6nEw4d+Mqa3XXAz0RFTZHunqqRj6sCt7Y_Eqqs0rw@mail.gmail.com/Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20211128172445.2616166-4-jic23@kernel.org

drivers/iio/adc/rcar-gyroadc.c

@@ -511,8 +511,7 @@ static int rcar_gyroadc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	priv->model = (enum rcar_gyroadc_model)
-		of_device_get_match_data(&pdev->dev);
+	priv->model = (uintptr_t)of_device_get_match_data(&pdev->dev);
 
 	platform_set_drvdata(pdev, indio_dev);