GPU Simple Governor: adapt GPU Simple Governor for Snapdrgaon 800 SOCs

initial coding for a Simple GPU governor based on my own work 2 years ago
from Sensation GB kernel commit: c1ea8f6

Signed-off-by: Paul Reioux <reioux@gmail.com>
Simple GPU governor: fix a merge derp

Signed-off-by: Paul Reioux <reioux@gmail.com>
defconfig: enable GPU simple governor