ppc32: move some dma routines

Every other architecture define dma_cache_{inv,wback,wback_inv}
in asm/io.h and doing so brings us closer to ppc64.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
diff --git a/include/asm-ppc/io.h b/include/asm-ppc/io.h
index 2bfdf9c..84ac6e2 100644
--- a/include/asm-ppc/io.h
+++ b/include/asm-ppc/io.h
@@ -545,6 +545,23 @@
 #include <asm/mpc8260_pci9.h>
 #endif
 
+#ifdef CONFIG_NOT_COHERENT_CACHE
+
+#define dma_cache_inv(_start,_size) \
+	invalidate_dcache_range(_start, (_start + _size))
+#define dma_cache_wback(_start,_size) \
+	clean_dcache_range(_start, (_start + _size))
+#define dma_cache_wback_inv(_start,_size) \
+	flush_dcache_range(_start, (_start + _size))
+
+#else
+
+#define dma_cache_inv(_start,_size)		do { } while (0)
+#define dma_cache_wback(_start,_size)		do { } while (0)
+#define dma_cache_wback_inv(_start,_size)	do { } while (0)
+
+#endif
+
 /*
  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
  * access