powerpc: Remove addr_needs_map in struct dma_mapping_ops

This patch adds max_direct_dma_addr to struct dev_archdata to remove
addr_needs_map in struct dma_mapping_ops. It also converts
dma_capable() to use max_direct_dma_addr.

max_direct_dma_addr is initialized in pci_dma_dev_setup_swiotlb(),
called via ppc_md.pci_dma_dev_setup hook.

For further information:
http://marc.info/?t=124719060200001&r=1&w=2

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/device.h b/arch/powerpc/include/asm/device.h
index 7d2277c..0086f8d 100644
--- a/arch/powerpc/include/asm/device.h
+++ b/arch/powerpc/include/asm/device.h
@@ -16,6 +16,9 @@
 	/* DMA operations on that device */
 	struct dma_mapping_ops	*dma_ops;
 	void			*dma_data;
+#ifdef CONFIG_SWIOTLB
+	dma_addr_t		max_direct_dma_addr;
+#endif
 };
 
 static inline void dev_archdata_set_node(struct dev_archdata *ad,