dma: import linux/dma-direction.h to consolidate enum dma_data_direction

Import include/linux/dma-direction.h from Linux 4.13-rc7 and delete
duplicated definitions of enum dma_data_direction.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/drivers/mmc/uniphier-sd.c b/drivers/mmc/uniphier-sd.c
index e272b14..721b75f 100644
--- a/drivers/mmc/uniphier-sd.c
+++ b/drivers/mmc/uniphier-sd.c
@@ -11,10 +11,10 @@
 #include <mmc.h>
 #include <dm.h>
 #include <linux/compat.h>
+#include <linux/dma-direction.h>
 #include <linux/io.h>
 #include <linux/sizes.h>
 #include <asm/unaligned.h>
-#include <asm/dma-mapping.h>
 
 DECLARE_GLOBAL_DATA_PTR;