Voltage Control: for HTC One X - codename evita - hybrid kernel m7 ge
base

This is a mixture of reverts of the following commits

Undervolt: add checks to disallow too extreme voltages, min and max.
5df9daa83862b545916e4514877fd3de8e549259

Undervolt: few minor changes, mostly for clarity.
f6260f9dd84718da05dfe1f88503a64a0072d810

Undervolt: clean it up, make it elegant and remove the constrain of f…
a005b7ac7e1dd4cfadd7af3f53f046eb7860f438
and a partial revert of

Mako (absolute) Voltage control.
8fe9b3549a67f96779d5cc42dd094fc754e63eec

a cherry-pick of

Voltage Control: add sysfs interface
723c1a6c1138d6e0a283d85e2346d1520974aa45

and finally a partial cherry-pick of

Voltage Control: initial voltage control for MSM S4-Pro SOC
7a13af42fb1617bad231ca58ced7d6be3be36563

Change-Id: I2ed2812123411012708cca69a749a3e3beb4c14a
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>
boosted7-r2

Change-Id: If7402546cfeee3da09772c5fe9a3064cee9621ff
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>