arm/m68k: Change mail address of Sebastian Hess

That old mail address doesnt exist any more.
This changes all occurences to a current address.

Signed-off-by: Oskar Schirmer <oskar@scara.com>
Acked-by: Sebastian Heß <shess@hessware.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>