dmaengine: mpc512x: 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: Mario Six <mario.six@gdsys.cc>

drivers/dma/mpc512x_dma.c

@@ -1110,6 +1110,7 @@ static int mpc_dma_remove(struct platform_device *op)
 	}
 	free_irq(mdma->irq, mdma);
 	irq_dispose_mapping(mdma->irq);
+	tasklet_kill(&mdma->tasklet);
 
 	return 0;
 }