serial: 8250_mtk: drop !defined(MODULE) conditional

The !defined(MODULE) conditional has been added to the
OF_EARLYCON_DECLARE() define.

This commit partially reverts commit 3f5921a60f74 ("serial:
8250/mediatek: fix building with SERIAL_8250=m").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_mtk.c

@@ -301,7 +301,7 @@ static struct platform_driver mtk8250_platform_driver = {
 };
 module_platform_driver(mtk8250_platform_driver);
 
-#if defined(CONFIG_SERIAL_8250_CONSOLE) && !defined(MODULE)
+#ifdef CONFIG_SERIAL_8250_CONSOLE
 static int __init early_mtk8250_setup(struct earlycon_device *device,
 					const char *options)
 {