clk: zx296718: use builtin_platform_driver to simplify the code

Use the builtin_platform_driver() macro to make the code simpler.
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

drivers/clk/zte/clk-zx296718.c

@@ -917,8 +917,4 @@ static struct platform_driver zx_clk_driver = {
 	},
 };
 
-static int __init zx_clkc_init(void)
-{
-	return platform_driver_register(&zx_clk_driver);
-}
-device_initcall(zx_clkc_init);
+builtin_platform_driver(zx_clk_driver);