powerpc: cache: define ARCH_DMA_MINALIGN for DMA buffer alignment

Signed-off-by: Anton Staaf <robotboy@chromium.org>
Acked-by: Stefan Roese <sr@denx.de>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Stefan Roese <sr@denx.de>
diff --git a/arch/powerpc/include/asm/cache.h b/arch/powerpc/include/asm/cache.h
index 53e8d05..e6b8f69 100644
--- a/arch/powerpc/include/asm/cache.h
+++ b/arch/powerpc/include/asm/cache.h
@@ -21,6 +21,12 @@
 #define L1_CACHE_BYTES          (1 << L1_CACHE_SHIFT)
 
 /*
+ * Use the L1 data cache line size value for the minimum DMA buffer alignment
+ * on PowerPC.
+ */
+#define ARCH_DMA_MINALIGN	L1_CACHE_BYTES
+
+/*
  * For compatibility reasons support the CONFIG_SYS_CACHELINE_SIZE too
  */
 #ifndef CONFIG_SYS_CACHELINE_SIZE