usb: dwc3: fix missing platform_set_drvdata() in dwc3_of_simple_probe()

Add missing platform_set_drvdata() in dwc3_of_simple_probe(), otherwise
calling platform_get_drvdata() in remove returns NULL.

This is detected by Coccinelle semantic patch.
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/dwc3-of-simple.c

@@ -61,6 +61,7 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
 	if (!simple->clks)
 		return -ENOMEM;
 
+	platform_set_drvdata(pdev, simple);
 	simple->dev = dev;
 
 	for (i = 0; i < simple->num_clocks; i++) {