Add GPU clock control. Allows users to overclock this GPU as much as their device handles (higher than 800MHz is unheard off since stock is 416MHz). It scales all the approriate busses and clocks accordingly so that we get a real overclock improvement and not fake omfgover9000 performance. It increases VDE voltages in 3 steps depending on how high the GPU max clocks are set by the users.

Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Local version bump (and clean crap from defconfig