iommu/exynos: Constify iommu_ops

iommu_ops are not supposed to change at runtime.
Functions 'iommu_device_set_ops' and 'bus_set_iommu' working with
const iommu_ops provided by <linux/iommu.h>. So mark the non-const
structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/exynos-iommu.c

@@ -565,7 +565,7 @@ static void sysmmu_tlb_invalidate_entry(struct sysmmu_drvdata *data,
 	spin_unlock_irqrestore(&data->lock, flags);
 }
 
-static struct iommu_ops exynos_iommu_ops;
+static const struct iommu_ops exynos_iommu_ops;
 
 static int __init exynos_sysmmu_probe(struct platform_device *pdev)
 {
@@ -1326,7 +1326,7 @@ static int exynos_iommu_of_xlate(struct device *dev,
 	return 0;
 }
 
-static struct iommu_ops exynos_iommu_ops = {
+static const struct iommu_ops exynos_iommu_ops = {
 	.domain_alloc = exynos_iommu_domain_alloc,
 	.domain_free = exynos_iommu_domain_free,
 	.attach_dev = exynos_iommu_attach_device,