usb: cdns3: imx: fix can't create core device the second time issue

The cdns3 core device is populated by calling of_platform_populate,
the flag OF_POPULATED is set for core device node, if this flag
is not cleared, when calling of_platform_populate the second time
after loading parent module again, the OF code will not try to create
platform device for core device.

To fix it, it uses of_platform_depopulate to depopulate the core
device which the parent created, and the flag OF_POPULATED for
core device node will be cleared accordingly.

Cc: <stable@vger.kernel.org>
Fixes: 1e056ef ("usb: cdns3: add NXP imx8qm glue layer")
Signed-off-by: Peter Chen <peter.chen@nxp.com>

Author: Peter Chen

drivers/usb/cdns3/cdns3-imx.c

@@ -218,20 +218,11 @@ static int cdns_imx_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int cdns_imx_remove_core(struct device *dev, void *data)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-
-	platform_device_unregister(pdev);
-
-	return 0;
-}
-
 static int cdns_imx_remove(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 
-	device_for_each_child(dev, NULL, cdns_imx_remove_core);
+	of_platform_depopulate(dev);
 	platform_set_drvdata(pdev, NULL);
 
 	return 0;