mali: GPU control

GPU frequency, scaling and voltage control. Based on netarchy's initial implementation and improvements of gokhanmoral and ported onto the pegasus-m400 / Galaxy S3 platform.

Signed-off-by: umberto1978 <ur.tecnotop@gmail.com>
Maybe the right way to make the gpu control work as expected.
This commit is inspired by AndreiLux, but adapted to the reviosion platform for N7100 update 2