dmaengine: mmp: deprecate '#dma-channels'

The generic property, used in most of the drivers and defined in generic
dma-common DT bindings, is 'dma-channels'.  Switch to new property while
keeping backward compatibility.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220503065407.52188-4-krzysztof.kozlowski@linaro.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/mmp_pdma.c

@@ -1043,13 +1043,17 @@ static int mmp_pdma_probe(struct platform_device *op)
 		return PTR_ERR(pdev->base);
 
 	of_id = of_match_device(mmp_pdma_dt_ids, pdev->dev);
-	if (of_id)
-		of_property_read_u32(pdev->dev->of_node, "#dma-channels",
-				     &dma_channels);
-	else if (pdata && pdata->dma_channels)
+	if (of_id) {
+		/* Parse new and deprecated dma-channels properties */
+		if (of_property_read_u32(pdev->dev->of_node, "dma-channels",
+					 &dma_channels))
+			of_property_read_u32(pdev->dev->of_node, "#dma-channels",
+					     &dma_channels);
+	} else if (pdata && pdata->dma_channels) {
 		dma_channels = pdata->dma_channels;
-	else
+	} else {
 		dma_channels = 32;	/* default 32 channel */
+	}
 	pdev->dma_channels = dma_channels;
 
 	for (i = 0; i < dma_channels; i++) {