firmware: imx: scu: change init level to subsys_initcall_sync

Change firmware init level to subsys_initcall_sync to ensure it's
probed before most devices to avoid unnecessary defer probe.

Signed-off-by: Dong Aisheng <[e-mail]>
Signed-off-by: Peng Fan <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

drivers/firmware/imx/imx-scu.c

···
 	},
 	.probe = imx_scu_probe,
 };
-builtin_platform_driver(imx_scu_driver);
+
+static int __init imx_scu_driver_init(void)
+{
+	return platform_driver_register(&imx_scu_driver);
+}
+subsys_initcall_sync(imx_scu_driver_init);
 
 MODULE_AUTHOR("Dong Aisheng <[e-mail]>");
 MODULE_DESCRIPTION("IMX SCU firmware protocol driver");