iommu: tegra/gart: use correct gart_device

Pass the correct gart device pointer.
Reviewed-by: Vandana Salve <vsalve@nvidia.com>
Tested-by: Vandana Salve <vsalve@nvidia.com>
Reviewed-by: Hiroshi Doyu <hdoyu@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Signed-off-by: Hiroshi DOYU <hdoyu@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

drivers/iommu/tegra-gart.c

@@ -158,7 +158,7 @@ static int gart_iommu_attach_dev(struct iommu_domain *domain,
 	struct gart_client *client, *c;
 	int err = 0;
 
-	gart = dev_get_drvdata(dev->parent);
+	gart = gart_handle;
 	if (!gart)
 		return -EINVAL;
 	domain->priv = gart;