opp: Update bandwidth requirements based on scaling up/down

The bandwidth must be scaled at a different point in the code flow based
on if we are scaling up or down the frequency, otherwise this may cause
undesired effects as the device will try to use more of the memory
bandwidth which may be shared across several devices. Much like how
regulators and required-opps are programmed.

Reported-by: Dmitry Osipenko <digetx@gmail.com>
Reported-by: Akhil P Oommen <akhilpo@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dmitry Osipenko <digetx@gmail.com>