iio: adc: ingenic-adc: Benefit from devm_clk_get_prepared() to simplify

Make use of devm_clk_get_prepared() to replace some code that effectively
open codes this new function.

Reviewed-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Uwe Kleine-König <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/adc/ingenic-adc.c

···
 	return -EINVAL;
 }
 
-static void ingenic_adc_clk_cleanup(void *data)
-{
-	clk_unprepare(data);
-}
-
 static const struct iio_info ingenic_adc_info = {
 	.write_raw = ingenic_adc_write_raw,
 	.read_raw = ingenic_adc_read_raw,
···
 	if (IS_ERR(adc->base))
 		return PTR_ERR(adc->base);
 
-	adc->clk = devm_clk_get(dev, "adc");
+	adc->clk = devm_clk_get_prepared(dev, "adc");
 	if (IS_ERR(adc->clk)) {
 		dev_err(dev, "Unable to get clock\n");
 		return PTR_ERR(adc->clk);
 	}
 
-	ret = clk_prepare_enable(adc->clk);
+	ret = clk_enable(adc->clk);
 	if (ret) {
 		dev_err(dev, "Failed to enable clock\n");
 		return ret;
···
 
 	usleep_range(2000, 3000); /* Must wait at least 2ms. */
 	clk_disable(adc->clk);
-
-	ret = devm_add_action_or_reset(dev, ingenic_adc_clk_cleanup, adc->clk);
-	if (ret) {
-		dev_err(dev, "Unable to add action\n");
-		return ret;
-	}
 
 	iio_dev->name = "jz-adc";
 	iio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;