DRIVERS: SLIMBUS: fix compile with Linaro 4.8.3 and -Ofast options
> initialize variables
slimbus: Add slimbus device driver unregistration function

slim_driver_unregister is added to reverse effects of
slim_driver_register. That way a slimbus device driver can be
registered when driver module is loaded, and unregistered when
the driver module is unloaded.

CRs-Fixed: 441540
Change-Id: Iae64f84c99d5027c9b55c3fde5fe71c6a550354e
Signed-off-by: Sagar Dharia <sdharia@codeaurora.org>
Signed-off-by: poondog <markj338@gmail.com>
slimbus: Handle channel control correctly if controller manages BW

If bandwidth allocation is managed by controller (and not framework),
channel control commands from all clients should be sent to the
controller.

Change-Id: Ibdd27c35a48818efdd55a0a84c52fbb9671cdb77
Signed-off-by: Sagar Dharia <sdharia@codeaurora.org>
Signed-off-by: poondog <markj338@gmail.com>