dmaengine: cppi41: Fix list not empty warning on module removal

If musb controller is configured with USB peripherals and we have
enumerated with a USB host, we can get warnings on removal of the
modules:

WARNING: CPU: 0 PID: 1269 at drivers/dma/cppi41.c:391
cppi41_dma_free_chan_resources

Fix the issue by adding the missing pm_runtime_get to
cppi41_dma_free_chan_resources to make sure the pending work
list is cleared on removal.

Fixes: fdea2d09 ("dmaengine: cppi41: Add basic PM runtime support")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/cppi41.c

@@ -1072,7 +1072,12 @@ static int cppi41_dma_probe(struct platform_device *pdev)
 static int cppi41_dma_remove(struct platform_device *pdev)
 {
 	struct cppi41_dd *cdd = platform_get_drvdata(pdev);
+	int error;
 
+	error = pm_runtime_get_sync(&pdev->dev);
+	if (error < 0)
+		dev_err(&pdev->dev, "%s could not pm_runtime_get: %i\n",
+			__func__, error);
 	of_dma_controller_free(pdev->dev.of_node);
 	dma_async_device_unregister(&cdd->ddev);