SERIAL: SC26xx: Fix link error.

Kconfig allows enabling console support for the SC26xx driver even when
it's configured as a module resulting in a:

ERROR: "uart_console_device" [drivers/tty/serial/sc26xx.ko] undefined!

modpost error since the driver was merged in
eea63e0e8a60d00485b47fb6e75d9aa2566b989b [SC26XX: New serial driver for
SC2681 uarts] in 2.6.25.  Fixed by only allowing console support to be
enabled if the driver is builtin.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: stable <stable@kernel.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/tty/serial/Kconfig

@@ -1419,7 +1419,7 @@ config SERIAL_SC26XX
 
 config SERIAL_SC26XX_CONSOLE
 	bool "Console on SC2681/SC2692 serial port"
-	depends on SERIAL_SC26XX
+	depends on SERIAL_SC26XX=y
 	select SERIAL_CORE_CONSOLE
 	help
 	  Support for Console on SC2681/SC2692 serial ports.