spi/s3c64xx: Take runtime PM reference even if DMA is not supported

We always need the device to be runtime PM enabled to use it so just skip
the DMA initialisation not the entire prepare when polling.

Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index a7a739c..eee1a7b 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -429,27 +429,26 @@
 	dma_cap_mask_t mask;
 	int ret;
 
-	if (is_polling(sdd))
-		return 0;
+	if (!is_polling(sdd)) {
+		dma_cap_zero(mask);
+		dma_cap_set(DMA_SLAVE, mask);
 
-	dma_cap_zero(mask);
-	dma_cap_set(DMA_SLAVE, mask);
+		/* Acquire DMA channels */
+		sdd->rx_dma.ch = dma_request_slave_channel_compat(mask, filter,
+				   (void *)sdd->rx_dma.dmach, dev, "rx");
+		if (!sdd->rx_dma.ch) {
+			dev_err(dev, "Failed to get RX DMA channel\n");
+			ret = -EBUSY;
+			goto out;
+		}
 
-	/* Acquire DMA channels */
-	sdd->rx_dma.ch = dma_request_slave_channel_compat(mask, filter,
-				(void *)sdd->rx_dma.dmach, dev, "rx");
-	if (!sdd->rx_dma.ch) {
-		dev_err(dev, "Failed to get RX DMA channel\n");
-		ret = -EBUSY;
-		goto out;
-	}
-
-	sdd->tx_dma.ch = dma_request_slave_channel_compat(mask, filter,
-				(void *)sdd->tx_dma.dmach, dev, "tx");
-	if (!sdd->tx_dma.ch) {
-		dev_err(dev, "Failed to get TX DMA channel\n");
-		ret = -EBUSY;
-		goto out_rx;
+		sdd->tx_dma.ch = dma_request_slave_channel_compat(mask, filter,
+				   (void *)sdd->tx_dma.dmach, dev, "tx");
+		if (!sdd->tx_dma.ch) {
+			dev_err(dev, "Failed to get TX DMA channel\n");
+			ret = -EBUSY;
+			goto out_rx;
+		}
 	}
 
 	ret = pm_runtime_get_sync(&sdd->pdev->dev);