Something is faulty and you should not ignore the problem, fix it while it's free. Just my suggestion. I'm not gonna try to figure out what exactly is whining, any electrical component can but normally does not create a pulse powerful enough for an audible sound. Saying it's voltage regulatory circuitry is like saying my car engine is making noise, only one piece of the puzzle and there's much more to it than that. Then you offer the solution of duct tape, problem solved.
No offense.
Cpus have been able to downclock themselves for a long time, like pentium 3. I don't refute that modern cpus have much more complex power management but that's beside the point. No matter how complex it is, it shouldn't make an audible sound.