DC: performance: gpu: rewrite fragment and add gpu governor

adds help sections to gpu as well

Change-Id: I99cbde1eda654db885a640359012fd286c775a21
DC: tools: we subscribe and dont risk FC's with casts

drop the casting and replace way with a subscribe and on event replace way

Change-Id: I2ce06aeb5b5c21d4ab3cfed586cda3eb4e6560df