gpu: kgsl: load based GPU scaling
  Initial commit.  Just setting some things up for now.
  Ideally, this will scale up the GPU based on load
  while paying attention to the max frequency allowed
  by the user.

  Credit for the idea goes to @franciscofgranco based
  on this commit:

  https://github.com/franciscofranco/mako/commit/caf8cf7387a5016990e00b1ded5563b7e7a11cb2