microblaze: Clean device dma_ops structure

No code is setting up dma_operation for device.
Use dma_direct_ops for all cases.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/microblaze/include/asm/device.h

@@ -12,8 +12,6 @@
 struct device_node;
 
 struct dev_archdata {
-	/* DMA operations on that device */
-	struct dma_map_ops	*dma_ops;
 };
 
 struct pdev_archdata {

arch/microblaze/include/asm/dma-mapping.h

@@ -50,16 +50,9 @@ extern struct dma_map_ops dma_direct_ops;
 
 static inline struct dma_map_ops *get_dma_ops(struct device *dev)
 {
-	if (dev && dev->archdata.dma_ops)
-		return dev->archdata.dma_ops;
 	return &dma_direct_ops;
 }
 
-static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
-{
-	dev->archdata.dma_ops = ops;
-}
-
 static inline int dma_supported(struct device *dev, u64 mask)
 {
 	struct dma_map_ops *ops = get_dma_ops(dev);