[POWERPC] Add of_translate_dma_address

This adds a variant of of_translate_address that uses the dma-ranges
property instead of "ranges", it's to be used by PCI code in parsing
the dma-ranges property.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/prom.h b/include/asm-powerpc/prom.h
index 925e2d3..78b7b0d 100644
--- a/include/asm-powerpc/prom.h
+++ b/include/asm-powerpc/prom.h
@@ -202,6 +202,10 @@
  */
 extern u64 of_translate_address(struct device_node *np, const u32 *addr);
 
+/* Translate a DMA address from device space to CPU space */
+extern u64 of_translate_dma_address(struct device_node *dev,
+				    const u32 *in_addr);
+
 /* Extract an address from a device, returns the region size and
  * the address space flags too. The PCI version uses a BAR number
  * instead of an absolute index