8250: uniphier: allow modular build with 8250 console

The recently added uniphier 8250 port driver supports early console
probing, and it supports being built as a module, but the combination
of the two fails to link:

ERROR: "early_serial8250_setup" [drivers/tty/serial/8250/8250_uniphier.ko] undefined!

Given that earlycon support in a loadable module makes no sense,
making that code conditional on 'MODULE' is a correct solution.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b8d20e06eaad ("serial: 8250_uniphier: add earlycon support")
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_uniphier.c

@@ -35,7 +35,7 @@ struct uniphier8250_priv {
 	spinlock_t atomic_write_lock;
 };
 
-#ifdef CONFIG_SERIAL_8250_CONSOLE
+#if defined(CONFIG_SERIAL_8250_CONSOLE) && !defined(MODULE)
 static int __init uniphier_early_console_setup(struct earlycon_device *device,
 					       const char *options)
 {