scripts/kernel-doc: drop maintainer

Drop maintainership of scripts/kernel-doc.
Patches can go thru the kbuild tree.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc:	Rob Landley <rob@landley.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>