fixup usage of dma direction by introducing dma_transfer_direction,
this patch moves samsung drivers to use new enum

Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Boojin Kim <boojin.kim@samsung.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>