spi: s3c64xx: fix casting warning

sdd->ops->request is unsigned int, not unsigned long.
Also, sdd->rx_dma.ch is a 'struct dma_chan *'.
Thus, (void *) is converted to (struct dma_chan *)(unsigned long),
in order to fix possible sparse warnings.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-s3c64xx.c

@@ -336,10 +336,10 @@ static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
 	req.cap = DMA_SLAVE;
 	req.client = &s3c64xx_spi_dma_client;
 
-	sdd->rx_dma.ch = (void *)sdd->ops->request(sdd->rx_dma.dmach,
-						&req, dev, "rx");
-	sdd->tx_dma.ch = (void *)sdd->ops->request(sdd->tx_dma.dmach,
-						&req, dev, "tx");
+	sdd->rx_dma.ch = (struct dma_chan *)(unsigned long)sdd->ops->request(
+					sdd->rx_dma.dmach, &req, dev, "rx");
+	sdd->tx_dma.ch = (struct dma_chan *)(unsigned long)sdd->ops->request(
+					sdd->tx_dma.dmach, &req, dev, "tx");
 
 	return 1;
 }