mali: add a new gpu scaling algorithm

this is a really simple algorithm that is probably screwed up in a lot of ways. didn't spend much time on this, especially the load thresholds. some bugs i found are that the freqs with the same load thresholds(e.g. 420mhz, 440mhz and 460mhz). the gpu does not scale over 420mhz probably due to the same load thresholds. too lazy to fix it though. i'll look at the load thresholds again in the future. until now, it works pretty well from 192mhz - 422mhz.
i also adjusted the boost delay to 250ms as i feel that 500ms is too large a difference for sensitive scaling. this can be improved though.

Change-Id: I3f296ca52608e4c00e93506c84a52f3cef189f53