spi, serial: move to dma_transfer_direction

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

Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@iki.fi>
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index b46218d..73201a1 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -747,7 +747,7 @@
 	sg_dma_address(sg) = priv->rx_buf_dma;
 
 	desc = priv->chan_rx->device->device_prep_slave_sg(priv->chan_rx,
-			sg, 1, DMA_FROM_DEVICE,
+			sg, 1, DMA_DEV_TO_MEM,
 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 
 	if (!desc)
@@ -906,7 +906,7 @@
 	}
 
 	desc = priv->chan_tx->device->device_prep_slave_sg(priv->chan_tx,
-					priv->sg_tx_p, nent, DMA_TO_DEVICE,
+					priv->sg_tx_p, nent, DMA_MEM_TO_DEV,
 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
 		dev_err(priv->port.dev, "%s:device_prep_slave_sg Failed\n",