dmengine: xilinx_dma: convert callback to helper function

Move the xilinx driver to new dmaengine callback

Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/xilinx/xilinx_dma.c

···
 	spin_lock_irqsave(&chan->lock, flags);
 
 	list_for_each_entry_safe(desc, next, &chan->done_list, node) {
-		dma_async_tx_callback callback;
-		void *callback_param;
+		struct dmaengine_desc_callback cb;
 
 		if (desc->cyclic) {
 			xilinx_dma_chan_handle_cyclic(chan, desc, &flags);
···
 		list_del(&desc->node);
 
 		/* Run the link descriptor callback function */
-		callback = desc->async_tx.callback;
-		callback_param = desc->async_tx.callback_param;
-		if (callback) {
+		dmaengine_desc_get_callback(&desc->async_tx, &cb);
+		if (dmaengine_desc_callback_valid(&cb)) {
 			spin_unlock_irqrestore(&chan->lock, flags);
-			callback(callback_param);
+			dmaengine_desc_callback_invoke(&cb, NULL);
 			spin_lock_irqsave(&chan->lock, flags);
 		}