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/ata/sata_dwc.c b/drivers/ata/sata_dwc.c
index a226ca2..2f3b2dd 100644
--- a/drivers/ata/sata_dwc.c
+++ b/drivers/ata/sata_dwc.c
@@ -26,6 +26,7 @@
 #include <command.h>
 #include <pci.h>
 #include <asm/processor.h>
+#include <linux/dma-direction.h>
 #include <linux/errno.h>
 #include <asm/io.h>
 #include <malloc.h>