msm: msm_bus: Add Bandwidth Monitor driver

Bandwidth Monitor driver is to create bandwidth sensor nodes
(logical nodes), that pertains to different bus routes and registers
them with the thermal core framework as thermal zone devices. So that
clients can monitor these devices as any other thermal zone devices
and can take actions based on requirement.

Bandwidth Monitor driver is going to register with bus driver
framework to get bandwidth vote notifications. As these bandwidth
sensors nodes are exposed as thermal zone devices, limits management
clients can set the thresholds to monitor whether bandwidth vote on a
particular bus route is crossing the some predefined threshold or not.
Upon receiving the notification for trigger threshold, client can
initiate the mitigation using available bandwidth mitigation knobs
like modem etc. and can clear it once bandwidth vote goes below clear
threshold. This design have multi client support as well.

Change-Id: I4197648fba7dc7b725b7511988cfca90d2a3df82
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>