libpayload: Remove unused timer/serial drivers

This patch removes several timer and serial drivers (and configs) that
were specific to platforms which have been dropped in coreboot.

Change-Id: I589ca7f1a3b479f1c2b1b668a175a71583441ac9
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/30029
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>

payloads/libpayload/drivers/serial/bg4cd.c

@@ -1,45 +0,0 @@
-/*
- * This file is part of the coreboot project.
- *
- * Copyright (C) 2014 Google Electronics
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-#include <libpayload-config.h>
-#include <libpayload.h>
-
-void serial_putchar(unsigned int c)
-{
-}
-
-int serial_havechar(void)
-{
-	return 0;
-}
-
-int serial_getchar(void)
-{
-	return 0;
-}
-
-static struct console_input_driver consin = {
-	.havekey = &serial_havechar,
-	.getchar = &serial_getchar
-};
-
-static struct console_output_driver consout = {
-	.putchar = &serial_putchar
-};
-
-void serial_console_init(void)
-{
-	console_add_input_driver(&consin);
-	console_add_output_driver(&consout);
-}