iommu/tegra: Fix incorrect size calculation

This driver uses a mixture of ways to get the size of a PTE,
tegra_smmu_set_pde() did it as sizeof(*pd) which became wrong when pd
switched to a struct tegra_pd.

Switch pd back to a u32* in tegra_smmu_set_pde() so the sizeof(*pd)
returns 4.

Fixes: 50568f8 ("iommu/terga: Do not use struct page as the handle for as->pd memory")
Reported-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Closes: https://lore.kernel.org/all/62e7f7fe-6200-4e4f-ad42-d58ad272baa6@tecnico.ulisboa.pt/
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Link: https://lore.kernel.org/r/0-v1-da7b8b3d57eb+ce-iommu_terga_sizeof_jgg@nvidia.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

Author: jgunthorpe

drivers/iommu/tegra-smmu.c

@@ -559,11 +559,11 @@ static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova,
 {
 	unsigned int pd_index = iova_pd_index(iova);
 	struct tegra_smmu *smmu = as->smmu;
-	struct tegra_pd *pd = as->pd;
+	u32 *pd = &as->pd->val[pd_index];
 	unsigned long offset = pd_index * sizeof(*pd);
 
 	/* Set the page directory entry first */
-	pd->val[pd_index] = value;
+	*pd = value;
 
 	/* The flush the page directory entry from caches */
 	dma_sync_single_range_for_device(smmu->dev, as->pd_dma, offset,