cpufreq: qcom-nvmem: Preserve PM domain votes in system suspend

>From the Linux point of view, the power domains used by the CPU must
stay always-on. This is because we still need the CPU to keep running
until the last instruction, which will typically be a firmware call that
shuts down the CPU cleanly.

At the moment the power domain votes (enable + performance state) are
dropped during system suspend, which means the CPU could potentially
malfunction while entering suspend.

We need to distinguish between two different setups used with
qcom-cpufreq-nvmem:

 1. CPR power domain: The backing regulator used by CPR should stay
    always-on in Linux; it is typically disabled automatically by
    hardware when the CPU enters a deep idle state. However, we
    should pause the CPR state machine during system suspend.

 2. RPMPD: The power domains used by the CPU should stay always-on
    in Linux (also across system suspend). The CPU typically only
    uses the *_AO ("active-only") variants of the power domai...