kdbus: add Makefile, Kconfig and MAINTAINERS entry

kdbus: add Makefile, Kconfig and MAINTAINERS entry

This patch hooks up the build system to actually compile the files
added by previous patches. It also adds an entry to MAINTAINERS to
direct people to Greg KH, David Herrmann, Djalal Harouni and me for
questions and patches.

Change-Id: Ibd6c440501c0674245c3e9971b6b28d57a7d8c11
Signed-off-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Osmialowski <p.osmialowsk@samsung.com>