add map/unmap_single_attr and map/unmap_sg_attr to struct dma_mapping_ops

This adds map/unmap_single_attr and map/unmap_sg_attr to struct
dma_mapping_ops. This enables us to move the dma operations in struct
ia64_machine_vector to struct dma_mapping_ops.

Note that we will remove map/unmap_sg and map/umap_single.

This is a preparation of struct dma_mapping_ops unification.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>