Revert "GPU: Go to 533 Mhz fix up the incorrect pll references for Mhz calculation: pushistiky"

This reverts commit 7c7a93fa6acc3573b9224055f959293791cf9c3c.
Revert "Try some GPU OC and see what happens"

This reverts commit 9c0bc2940b46e6794bc06cbe98f2d00141e01b25.
GPU: OC: A nice little way to modify pll15_config.l on the fly to provide OC steps of 504, 544 and 600.  Still trying to find a way to reflect tha actual max_gpuclk, all commented code still wont allow it, will look at agin at a later date