console: Add weak method to notify about death

Call weak method die_notify.

The method should be overwritten in mainboard directory to signal that
a fatal error had occurred. On boards that do share the same EC and where
the EC is capable of controlling LEDs or a buzzer the method can be
overwritten in EC directory instead.

Tested on Lenovo T500.

Change-Id: I71f8ddfc96047e8a0d39f084588db1fe2f251612
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/19696
Reviewed-by: Martin Roth <martinroth@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/include/console/console.h

@@ -42,6 +42,12 @@ void post_log_clear(void);
 void mainboard_post(u8 value);
 void __attribute__((noreturn)) die(const char *msg);
 
+/*
+ * This function is weak and can be overridden to provide additional
+ * feedback to the user. Possible use case: Play a beep.
+ */
+void die_notify(void);
+
 #define __CONSOLE_ENABLE__ \
 	((ENV_BOOTBLOCK && IS_ENABLED(CONFIG_BOOTBLOCK_CONSOLE)) || \
 	(ENV_POSTCAR && IS_ENABLED(CONFIG_POSTCAR_CONSOLE)) || \