msm: camera: isp: Delay the change in BW during stop

Change the sequence of reducing the BW and stopping resources
during stop_hw to ensure BW is high until all the resources are
stopped. This will ensure that there are no overflow errors related
to BW during stop.

Change-Id: I0a4a74d56dc826ea3c0ad8f73d67ee2a16f22566
Signed-off-by: Harsh Shah <harshs@codeaurora.org>