iommu/omap: Drop redundant check if ti,syscon-mmuconfig exists

The syscon_regmap_lookup_by_phandle() will fail if property does not
exist, so doing of_property_read_bool() earlier is redundant.  Drop that
check and move error message to syscon_regmap_lookup_by_phandle() error
case while converting it to dev_err_probe().

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20250624-syscon-phandle-args-iommu-v3-1-1a36487d69b8@linaro.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

Author: krzk

drivers/iommu/omap-iommu.c

@@ -1123,23 +1123,15 @@ static int omap_iommu_dra7_get_dsp_system_cfg(struct platform_device *pdev,
 					      struct omap_iommu *obj)
 {
 	struct device_node *np = pdev->dev.of_node;
-	int ret;
 
 	if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
 		return 0;
 
-	if (!of_property_read_bool(np, "ti,syscon-mmuconfig")) {
-		dev_err(&pdev->dev, "ti,syscon-mmuconfig property is missing\n");
-		return -EINVAL;
-	}
-
 	obj->syscfg =
 		syscon_regmap_lookup_by_phandle(np, "ti,syscon-mmuconfig");
-	if (IS_ERR(obj->syscfg)) {
-		/* can fail with -EPROBE_DEFER */
-		ret = PTR_ERR(obj->syscfg);
-		return ret;
-	}
+	if (IS_ERR(obj->syscfg))
+		return dev_err_probe(&pdev->dev, PTR_ERR(obj->syscfg),
+				     "ti,syscon-mmuconfig property is missing\n");
 
 	if (of_property_read_u32_index(np, "ti,syscon-mmuconfig", 1,
 				       &obj->id)) {