PM: domains: Improve runtime PM performance state handling

GENPD core doesn't support handling performance state changes while
consumer device is runtime-suspended or when runtime PM is disabled.
GENPD core may override performance state that was configured by device
driver while RPM of the device was disabled or device was RPM-suspended.

Let's close that gap by allowing drivers to control performance state
while RPM of a consumer device is disabled and to set up performance
state of RPM-suspended device that will be applied by GENPD core on
RPM-resume of the device.

Fixes: 5937c3ce

 ("PM: domains: Drop/restore performance state votes for devices at runtime PM")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>