iommu: qcom: annotate PM functions as __maybe_unused

The qcom_iommu_disable_clocks() function is only called from PM
code that is hidden in an #ifdef, causing a harmless warning without
CONFIG_PM:

drivers/iommu/qcom_iommu.c:601:13: error: 'qcom_iommu_disable_clocks' defined but not used [-Werror=unused-function]
 static void qcom_iommu_disable_clocks(struct qcom_iommu_dev *qcom_iommu)
drivers/iommu/qcom_iommu.c:581:12: error: 'qcom_iommu_enable_clocks' defined but not used [-Werror=unused-function]
 static int qcom_iommu_enable_clocks(struct qcom_iommu_dev *qcom_iommu)

Replacing that #ifdef with __maybe_unused annotations lets the compiler
drop the functions silently instead.

Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu")
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/qcom_iommu.c

@@ -860,8 +860,7 @@ static int qcom_iommu_device_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM
-static int qcom_iommu_resume(struct device *dev)
+static int __maybe_unused qcom_iommu_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct qcom_iommu_dev *qcom_iommu = platform_get_drvdata(pdev);
@@ -869,7 +868,7 @@ static int qcom_iommu_resume(struct device *dev)
 	return qcom_iommu_enable_clocks(qcom_iommu);
 }
 
-static int qcom_iommu_suspend(struct device *dev)
+static int __maybe_unused qcom_iommu_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct qcom_iommu_dev *qcom_iommu = platform_get_drvdata(pdev);
@@ -878,7 +877,6 @@ static int qcom_iommu_suspend(struct device *dev)
 
 	return 0;
 }
-#endif
 
 static const struct dev_pm_ops qcom_iommu_pm_ops = {
 	SET_RUNTIME_PM_OPS(qcom_iommu_suspend, qcom_iommu_resume, NULL)