Power HAL: Remove sampling rate change

Sampling rate change causes stutter while playing music.
Stutter appears randomly, but has a higher chance of appearing
when the screen goes from off to on.

Change-Id: I9b23212165203c7ff7ef65021be09fd366e55770
exynos3: power HAL: add support for interactive governor

completely kanged from d2 power HAL

Change-Id: I4f6c32165251ae76c97afb715dde1fee9544430b