iommu/renesas: Use accessor functions for iommu private data

Make use of dev_iommu_priv_set/get() functions.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20200326150841.10083-13-joro@8bytes.org

drivers/iommu/ipmmu-vmsa.c

@@ -89,9 +89,7 @@ static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
 
 static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
 {
-	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
-
-	return fwspec ? fwspec->iommu_priv : NULL;
+	return dev_iommu_priv_get(dev);
 }
 
 #define TLB_LOOP_TIMEOUT		100	/* 100us */
@@ -727,14 +725,13 @@ static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
 static int ipmmu_init_platform_device(struct device *dev,
 				      struct of_phandle_args *args)
 {
-	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 	struct platform_device *ipmmu_pdev;
 
 	ipmmu_pdev = of_find_device_by_node(args->np);
 	if (!ipmmu_pdev)
 		return -ENODEV;
 
-	fwspec->iommu_priv = platform_get_drvdata(ipmmu_pdev);
+	dev_iommu_priv_set(dev, platform_get_drvdata(ipmmu_pdev));
 
 	return 0;
 }