dmaengine: replace dma_async_client_register with dmaengine_get

Now that clients no longer need to be notified of channel arrival
dma_async_client_register can simply increment the dmaengine_ref_count.

Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

net/core/dev.c

@@ -4894,8 +4894,7 @@ static int __init netdev_dma_register(void)
 	}
 	spin_lock_init(&net_dma.lock);
 	dma_cap_set(DMA_MEMCPY, net_dma.client.cap_mask);
-	dma_async_client_register(&net_dma.client);
-	dma_async_client_chan_request(&net_dma.client);
+	dmaengine_get();
 	return 0;
 }