dmaengine: sirf-dma: 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: Barry Song <Baohua.Song@csr.com>

drivers/dma/sirf-dma.c

@@ -980,6 +980,7 @@ static int sirfsoc_dma_remove(struct platform_device *op)
 	of_dma_controller_free(op->dev.of_node);
 	dma_async_device_unregister(&sdma->dma);
 	free_irq(sdma->irq, sdma);
+	tasklet_kill(&sdma->tasklet);
 	irq_dispose_mapping(sdma->irq);
 	pm_runtime_disable(&op->dev);
 	if (!pm_runtime_status_suspended(&op->dev))