Revert "sched/rt: Remove redundant nr_cpus_allowed test"

This reverts commit c94ad71c0360c66bc401ef0fcef165f36d054ee3.
Battery Friend: Fix storing of stock frequencies

Whether the user-defiend frequencies (policy->min, screen_on_max_freq) or stock-defined default frequencies weren't stored correctly so BF wasn't able to restore them correclty. A side effect was that BF couldn't lock the policy->min at the user-defined frequency for suspend. This should fix the handling (hopefully)