iommu/rockchip: Add map_sg callback for rk_iommu_ops

The iommu_dma_alloc() in iommu/dma-iommu.c calls iommu_map_sg()
that requires the callback iommu_ops .map_sg(). Adding the
default_iommu_map_sg() to Rockchip IOMMU accordingly.
Signed-off-by: Simon Xue <xxm@rock-chips.com>
Signed-off-by: Shunqian Zheng <xxm@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/rockchip-iommu.c

@@ -1022,6 +1022,7 @@ static const struct iommu_ops rk_iommu_ops = {
 	.detach_dev = rk_iommu_detach_device,
 	.map = rk_iommu_map,
 	.unmap = rk_iommu_unmap,
+	.map_sg = default_iommu_map_sg,
 	.add_device = rk_iommu_add_device,
 	.remove_device = rk_iommu_remove_device,
 	.iova_to_phys = rk_iommu_iova_to_phys,