Revert "Overclock GPU 2D plus a few 3D tweaks"

This reverts commit 20e1355a21853c5d18af6a4f1b69ee4067672194.
kgsl: gpu: update max power levels
kgsl: gpu: fix 3D frequency scaling

Existing logic had redundant code and wasn't exactly
efficient in scaling the governor.  Removed unnecessary
logic and cleaned it up a bit.
gpu: add 228MHz & 266MHz 2D gpu frequencies
Upgrade to BFQ-V6r2