qcom: clock-cpu-8994: Control A57 CPU workload when switching freqs

Simulations have shown that in extreme workload cases,
it is easier on the power distribution network to have
the A57 CPUs execute less-power-intensive code while the
A57 cluster is switching frequencies.

Change-Id: Ib6a70df4ddda4709181f639154e9edf10800310c
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>