tty: add TIOCVHANGUP to allow clean tty shutdown of all ttys

This is useful for system management software so that it can kick
off things like gettys and everything that's started from a tty,
before we reuse it from/for something else or shut it down.

Without this ioctl it would have to temporarily become the owner of
the tty, then call vhangup() and then give it up again.

Cc: Lennart Poettering <lennart@poettering.net>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/arch/parisc/include/asm/ioctls.h b/arch/parisc/include/asm/ioctls.h
index 6ba80d0..054ec06 100644
--- a/arch/parisc/include/asm/ioctls.h
+++ b/arch/parisc/include/asm/ioctls.h
@@ -54,6 +54,7 @@
 #define TIOCSPTLCK	_IOW('T',0x31, int)  /* Lock/unlock Pty */
 #define TIOCGDEV	_IOR('T',0x32, int)  /* Get primary device node of /dev/console */
 #define TIOCSIG		_IOW('T',0x36, int)  /* Generate signal on Pty slave */
+#define TIOCVHANGUP	0x5437
 
 #define FIONCLEX	0x5450  /* these numbers need to be adjusted. */
 #define FIOCLEX		0x5451