i2c: rcar: use dma_request_chan()

New drivers should not use dma_request_slave_channel_reason() but
dma_request_chan(). The former is a macro to the later so this change do
not effect the driver in any way.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-rcar.c

@@ -623,7 +623,7 @@ static struct dma_chan *rcar_i2c_request_dma_chan(struct device *dev,
 	char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx";
 	int ret;
 
-	chan = dma_request_slave_channel_reason(dev, chan_name);
+	chan = dma_request_chan(dev, chan_name);
 	if (IS_ERR(chan)) {
 		ret = PTR_ERR(chan);
 		dev_dbg(dev, "request_channel failed for %s (%d)\n",