dmaengine: fsl-qdma: Handle invalid qdma-queue0 IRQ

platform_get_irq_byname() might return -errno which later would be cast
to an unsigned int and used in IRQ handling code leading to usage of
wrong ID and errors about wrong irq_base.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Peng Ma <peng.ma@nxp.com>
Tested-by: Peng Ma <peng.ma@nxp.com>
Link: https://lore.kernel.org/r/20191004150826.6656-1-krzk@kernel.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/fsl-qdma.c

@@ -1155,6 +1155,9 @@ static int fsl_qdma_probe(struct platform_device *pdev)
 		return ret;
 
 	fsl_qdma->irq_base = platform_get_irq_byname(pdev, "qdma-queue0");
+	if (fsl_qdma->irq_base < 0)
+		return fsl_qdma->irq_base;
+
 	fsl_qdma->feature = of_property_read_bool(np, "big-endian");
 	INIT_LIST_HEAD(&fsl_qdma->dma_dev.channels);