mtd: nand: include <asm/cache.h> from include/linux/mtd/rawnand.h

This is needed for ARCH_DMA_MINALIGN.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 192709b..6c3e838 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -20,6 +20,7 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/flashchip.h>
 #include <linux/mtd/bbm.h>
+#include <asm/cache.h>
 
 struct mtd_info;
 struct nand_flash_dev;