iommu/exynos: Use the devm_clk_get_optional() helper

Use devm_clk_get_optional() instead of hand writing it.
This saves some loC and improves the semantic.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/99c0d5ce643737ee0952df41fd60433a0bbeb447.1679834256.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: tititiou36

drivers/iommu/exynos-iommu.c

@@ -747,33 +747,25 @@ static int exynos_sysmmu_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	data->clk = devm_clk_get(dev, "sysmmu");
-	if (PTR_ERR(data->clk) == -ENOENT)
-		data->clk = NULL;
-	else if (IS_ERR(data->clk))
+	data->clk = devm_clk_get_optional(dev, "sysmmu");
+	if (IS_ERR(data->clk))
 		return PTR_ERR(data->clk);
 
-	data->aclk = devm_clk_get(dev, "aclk");
-	if (PTR_ERR(data->aclk) == -ENOENT)
-		data->aclk = NULL;
-	else if (IS_ERR(data->aclk))
+	data->aclk = devm_clk_get_optional(dev, "aclk");
+	if (IS_ERR(data->aclk))
 		return PTR_ERR(data->aclk);
 
-	data->pclk = devm_clk_get(dev, "pclk");
-	if (PTR_ERR(data->pclk) == -ENOENT)
-		data->pclk = NULL;
-	else if (IS_ERR(data->pclk))
+	data->pclk = devm_clk_get_optional(dev, "pclk");
+	if (IS_ERR(data->pclk))
 		return PTR_ERR(data->pclk);
 
 	if (!data->clk && (!data->aclk || !data->pclk)) {
 		dev_err(dev, "Failed to get device clock(s)!\n");
 		return -ENOSYS;
 	}
 
-	data->clk_master = devm_clk_get(dev, "master");
-	if (PTR_ERR(data->clk_master) == -ENOENT)
-		data->clk_master = NULL;
-	else if (IS_ERR(data->clk_master))
+	data->clk_master = devm_clk_get_optional(dev, "master");
+	if (IS_ERR(data->clk_master))
 		return PTR_ERR(data->clk_master);
 
 	data->sysmmu = dev;