iommu/exynos: Make exynos_sysmmu_disable static

'exynos_sysmmu_disable' is used only in this file and can be made static.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

drivers/iommu/exynos-iommu.c

@@ -511,7 +511,7 @@ int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
 	return ret;
 }
 
-bool exynos_sysmmu_disable(struct device *dev)
+static bool exynos_sysmmu_disable(struct device *dev)
 {
 	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
 	bool disabled;