dmaengine: mxs-dma: use dmaenginem_async_device_register to simplify the code

Use dmaenginem_async_device_register to simplify the code:
	remove dma_async_device_unregister.
Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/mxs-dma.c

@@ -847,7 +847,7 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
 	mxs_dma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
 	mxs_dma->dma_device.device_issue_pending = mxs_dma_enable_chan;
 
-	ret = dma_async_device_register(&mxs_dma->dma_device);
+	ret = dmaenginem_async_device_register(&mxs_dma->dma_device);
 	if (ret) {
 		dev_err(mxs_dma->dma_device.dev, "unable to register\n");
 		return ret;
@@ -857,7 +857,6 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
 	if (ret) {
 		dev_err(mxs_dma->dma_device.dev,
 			"failed to register controller\n");
-		dma_async_device_unregister(&mxs_dma->dma_device);
 	}
 
 	dev_info(mxs_dma->dma_device.dev, "initialized\n");