dmaengine: nbpfaxi: kill the tasklets upon exit

drivers should ensure that tasklets are killed, so that they can't be
run after driver remove is executed

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Cc: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>

drivers/dma/nbpfaxi.c

@@ -1456,6 +1456,8 @@ static int nbpf_remove(struct platform_device *pdev)
 		struct nbpf_channel *chan = nbpf->chan + i;
 
 		devm_free_irq(&pdev->dev, chan->irq, chan);
+
+		tasklet_kill(&chan->tasklet);
 	}
 
 	of_dma_controller_free(pdev->dev.of_node);