usb: dwc3: exynos: Fix remove() function

The core DWC3 device node was not properly removed by the custom
dwc3_exynos_remove_child() function. Replace it with generic
of_platform_depopulate() which does that job right.

Fixes: adcf20dcd262 ("usb: dwc3: exynos: Use of_platform API to create dwc3 core pdev")
Signed-off-by: Marek Szyprowski <[e-mail]>
Acked-by: Thinh Nguyen <[e-mail]>
Cc: [e-mail]
Reviewed-by: Sam Protsenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/dwc3/dwc3-exynos.c

···
 	struct regulator	*vdd10;
 };
 
-static int dwc3_exynos_remove_child(struct device *dev, void *unused)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-
-	platform_device_unregister(pdev);
-
-	return 0;
-}
-
 static int dwc3_exynos_probe(struct platform_device *pdev)
 {
 	struct dwc3_exynos	*exynos;
···
 	struct dwc3_exynos	*exynos = platform_get_drvdata(pdev);
 	int i;
 
-	device_for_each_child(&pdev->dev, NULL, dwc3_exynos_remove_child);
+	of_platform_depopulate(&pdev->dev);
 
 	for (i = exynos->num_clks - 1; i >= 0; i--)
 		clk_disable_unprepare(exynos->clks[i]);