MAINTAINERS: mark ARM/PALM TREO SUPPORT orphan

The email address sleep_walker@suse.com and the url http://hackndev.com/

,
provided in the ARM/PALM TREO SUPPORT section, are not reachable anymore.

Make this machine support orphan, and give somebody the chance to step up.
Move the maintainer into CREDITS to keep the attribution to his work.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>