arm: build fix

arch/arm/common/dmabounce.c: In function 'dma_map_sg':
arch/arm/common/dmabounce.c:445: error: implicit declaration of function 'sg_page'

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index 9d371e4..52fc6a8 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -29,6 +29,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/dmapool.h>
 #include <linux/list.h>
+#include <linux/scatterlist.h>
 
 #include <asm/cacheflush.h>