[PATCH] remove MAINTAINERS entry for rtlinux

It's already big enough and there's no reason to list maintainers of
external patches.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>