Reduce readahead to 256

Change-Id: Ib5ca93def72590b511013095f6eac4fd5cb6affd
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>
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.

Undervolt: few minor changes, mostly for clarity.

Undervolt: clean it up, make it elegant and remove the constrain of f…

and a partial revert of

Mako (absolute) Voltage control.

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>