MAINTAINERS: Maik has moved

Maik is no longer using the plusserver.de email, update with his
current email.

Link: http://lkml.kernel.org/r/1473007794-27960-1-git-send-email-sudipm.mukherjee@gmail.com


Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Cc: Maik Broemme <mbroemme@libmpq.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>