Add support for suspending and resuming the whole console subsystem

Trying to suspend/resume with console messages flying all around is
doomed to failure, when the devices that the messages are trying to
go to are being shut down.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/console.h

@@ -117,6 +117,10 @@ extern void console_stop(struct console *);
 extern void console_start(struct console *);
 extern int is_console_locked(void);
 
+/* Suspend and resume console messages over PM events */
+extern void suspend_console(void);
+extern void resume_console(void);
+
 /* Some debug stub to catch some of the obvious races in the VT code */
 #if 1
 #define WARN_CONSOLE_UNLOCKED()	WARN_ON(!is_console_locked() && !oops_in_progress)