dmaengine: bcm2835: Print error in case setting DMA mask fails

During enabling of the RPi 4, we found out that the driver doesn't provide
a helpful error message in case setting DMA mask fails. So add one.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/1563297318-4900-1-git-send-email-wahrenst@gmx.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/bcm2835-dma.c

@@ -871,8 +871,10 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
 		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
 
 	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
-	if (rc)
+	if (rc) {
+		dev_err(&pdev->dev, "Unable to set DMA mask\n");
 		return rc;
+	}
 
 	od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
 	if (!od)