Revert "fix flashing buttons: add power.exynos5.so as proprietary blob from sammyNH1"

This reverts commit f8132950a061de30243c9f8f7dea78dead76acc8.
Revert "fix buttons: no need for PowerHAL - KeyDisabler does this on chagall."

This reverts commit 632df30bb10921ce940dc66155a87c9dcec081b2.