iio: adc: cc10001: use devm_platform_ioremap_resource

Reduces local boilerplate.
Found by coccinelle:

drivers/iio/adc/cc10001_adc.c:344:1-18: WARNING: Use devm_platform_ioremap_resource for adc_dev -> reg_base
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: Naidu Tellapati <naidu.tellapati@imgtec.com>

drivers/iio/adc/cc10001_adc.c

@@ -310,7 +310,6 @@ static int cc10001_adc_probe(struct platform_device *pdev)
 	struct device_node *node = pdev->dev.of_node;
 	struct cc10001_adc_device *adc_dev;
 	unsigned long adc_clk_rate;
-	struct resource *res;
 	struct iio_dev *indio_dev;
 	unsigned long channel_map;
 	int ret;
@@ -340,8 +339,7 @@ static int cc10001_adc_probe(struct platform_device *pdev)
 	indio_dev->info = &cc10001_adc_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res);
+	adc_dev->reg_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(adc_dev->reg_base)) {
 		ret = PTR_ERR(adc_dev->reg_base);
 		goto err_disable_reg;