KGSL: Add a simple GPU governor for Adreno xxx GPU series

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>
Modified for the latest Adreno drivers

Signed-off-by: faux123 <reioux@gmail.com>

Conflicts:
	drivers/gpu/msm/Kconfig
	drivers/gpu/msm/kgsl_pwrscale_trustzone.c