msm: msm_bus: Introduce adhoc bus topology

Introduce bus scaling driver to support adhoc bus topologies. Adhoc
bus topologies allow one to many device connections. This driver will
be used to setup bus topologies and apply client bandwidth requests
between specified endpoints.

Change-Id: Id8a5e4e41b202b3177f3ef0a8827c63aeec5de57
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>