um: Add myself as co-maintainer

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-and-appreciated-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS

@@ -6633,6 +6633,7 @@ F:	drivers/media/video/zr364xx.c
 
 USER-MODE LINUX (UML)
 M:	Jeff Dike <jdike@addtoit.com>
+M:	Richard Weinberger <richard@nod.at>
 L:	user-mode-linux-devel@lists.sourceforge.net
 L:	user-mode-linux-user@lists.sourceforge.net
 W:	http://user-mode-linux.sourceforge.net