DMAEngine: add dmaengine_prep_interleaved_dma wrapper for interleaved api

commit b14dab79(DMAEngine: Define interleaved transfer request api) adds
interleaved request api, this patch adds the dmaengine_prep_interleaved_dma
just like we have dmaengine_prep_ for other modes to avoid drivers call:
xxx_chan->device->device_prep_interleaved_dma().
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

include/linux/dmaengine.h

@@ -660,6 +660,13 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic(
 						period_len, dir, flags, NULL);
 }
 
+static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma(
+		struct dma_chan *chan, struct dma_interleaved_template *xt,
+		unsigned long flags)
+{
+	return chan->device->device_prep_interleaved_dma(chan, xt, flags);
+}
+
 static inline int dmaengine_terminate_all(struct dma_chan *chan)
 {
 	return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0);