microblaze: Support DMA

Add DMA support for Microblaze. There are some part of this new feature:
1. Basic DMA support
2. Enable DMA debug option
3. Setup notifier

Ad 1. dma-mapping come from powerpc and x86 version and it is based on
generic dma-mapping-common.h

Ad 2. DMA support debug features which is used in generic file.
For more information please look at Documentation/DMA-API.txt

Ad 3. notifier is very important to setup dma_ops. Without this part
for example ll_temac driver failed because there are no setup dma operations.

Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/include/asm/device.h b/arch/microblaze/include/asm/device.h
index 78a0384..402b46e 100644
--- a/arch/microblaze/include/asm/device.h
+++ b/arch/microblaze/include/asm/device.h
@@ -14,6 +14,10 @@
 struct dev_archdata {
 	/* Optional pointer to an OF device node */
 	struct device_node	*of_node;
+
+	/* DMA operations on that device */
+	struct dma_map_ops	*dma_ops;
+	void                    *dma_data;
 };
 
 struct pdev_archdata {