MAINTAINERS: Remove myself as nvec co-maintainer

My device broke a long time ago, so I do not have any
chance of testing things or any reason to continue
maintaining it.

Signed-off-by: Julian Andres Klode <jak@jak-linux.org>
Signed-off-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>