iommu/tegra: gart: Provide default ->map_sg() callback

Commit 315786ebbf4a ("iommu: Add iommu_map_sg() function") adds a new
->map_sg() callback and provides a default implementation that drivers
can use until they implement a hardware-specific variant. Unfortunately
the Tegra GART driver was not updated as part of that commit, so that
iommu_map_sg() calls on a domain provided by the GART cause an oops.

Fixes: 315786ebbf4a ("iommu: Add iommu_map_sg() function")
Cc: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index 10fc32d..c48da05 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -315,6 +315,7 @@
 	.attach_dev	= gart_iommu_attach_dev,
 	.detach_dev	= gart_iommu_detach_dev,
 	.map		= gart_iommu_map,
+	.map_sg		= default_iommu_map_sg,
 	.unmap		= gart_iommu_unmap,
 	.iova_to_phys	= gart_iommu_iova_to_phys,
 	.pgsize_bitmap	= GART_IOMMU_PGSIZES,