Voltage Control: add sysfs interface

Signed-off-by: faux123 <reioux@gmail.com>
Add GPU voltage control

Signed-off-by: Tk-Glitch <Ti3noU@gmail.com>

Conflicts:
	arch/arm/configs/cyanogen_d2dcm_defconfig
Add 480MHz GPU OC step
Fix an error with GPU OC
Add 500MHz GPU Step
Merge branch 'Deathly-4.4-Test' of https://github.com/LiquidSmooth/android_kernel_samsung_d2 into Deathly-4.4-Test