dmaengine: apple-admac: Fix grabbing of channels in of_xlate

The of_xlate callback is supposed to return the channel after already
having 'grabbed' it for private use, so fill that in.

Fixes: b127315d ("dmaengine: apple-admac: Add Apple ADMAC driver")
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20221019132324.8585-1-povik+lin@cutebit.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/apple-admac.c

@@ -493,7 +493,7 @@ static struct dma_chan *admac_dma_of_xlate(struct of_phandle_args *dma_spec,
 		return NULL;
 	}
 
-	return &ad->channels[index].chan;
+	return dma_get_slave_channel(&ad->channels[index].chan);
 }
 
 static int admac_drain_reports(struct admac_data *ad, int channo)