dmaengine: Add wrapper for device_tx_status callback

This patch adds a small inline wrapper for the devivce_tx_status callback of a
dma device. This makes the source code of users of this function a bit more
compact and a bit more legible.

E.g.:
-status = chan->device->device_tx_status(chan, cookie, &state)
+status = dmaengine_tx_status(chan, cookie, &state)

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/linux/dmaengine.h

@@ -670,6 +670,12 @@ static inline int dmaengine_resume(struct dma_chan *chan)
 	return dmaengine_device_control(chan, DMA_RESUME, 0);
 }
 
+static inline enum dma_status dmaengine_tx_status(struct dma_chan *chan,
+	dma_cookie_t cookie, struct dma_tx_state *state)
+{
+	return chan->device->device_tx_status(chan, cookie, state);
+}
+
 static inline dma_cookie_t dmaengine_submit(struct dma_async_tx_descriptor *desc)
 {
 	return desc->tx_submit(desc);