treewide: Consolidate set_dma_ops() implementations

Now that all set_dma_ops() implementations are identical (ignoring
BUG_ON() statements), remove the architecture specific definitions
and add a definition in <linux/dma-mapping.h>.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index f1da68b..e97f23e 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -164,6 +164,11 @@ int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
 
 #ifdef CONFIG_HAS_DMA
 #include <asm/dma-mapping.h>
+static inline void set_dma_ops(struct device *dev,
+			       const struct dma_map_ops *dma_ops)
+{
+	dev->dma_ops = dma_ops;
+}
 #else
 /*
  * Define the dma api to allow compilation but not linking of