cpufreq: mediatek: add missing platform_driver_unregister() on error in mtk_cpufreq_driver_init

Add the missing platform_driver_unregister() before return from
mtk_cpufreq_driver_init in the error handling case when failed
to register mtk-cpufreq platform device

Signed-off-by: Qinglang Miao <[e-mail]>
Signed-off-by: Viresh Kumar <[e-mail]>

drivers/cpufreq/mediatek-cpufreq.c

···
 	pdev = platform_device_register_simple("mtk-cpufreq", -1, NULL, 0);
 	if (IS_ERR(pdev)) {
 		pr_err("failed to register mtk-cpufreq platform device\n");
+		platform_driver_unregister(&mtk_cpufreq_platdrv);
 		return PTR_ERR(pdev);
 	}