spi: Compatibility with direction which is used in samsung DMA operation

I found that there are two kind of direction type.
First one is dma_data_direction defined in include/linux/dma-direction.h.
It is used for parameter of dma_map/unmap_single in spi-s3c64xx.
The other one is dma_transter_direction defined in include/linux/dmaengine.h.
It is used for direction of samsung DMA operation
(arch/arm/plat-samsung/dma-ops.c).
This patch is just some changes to use direction defines
which is used in samsung DMA operation.

Signed-off-by: Boojin Kim <boojin.kim@samsung.com>
Signed-off-by: Kyoungil Kim <ki0351.kim@samsung.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>