[PATCH] MAINTAINERS: remove the non-existing sun3 list

sun3-list@redhat.com does no longer exist.

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