Revert "Revert "cpufreq: Add cpu-boost driver""

This reverts commit 2f92426f74fe27d8912608b574c56786b89ac983.
Revert "Revert "cpufreq: Add a sync limit to cpu-boost""

This reverts commit 79c997607137ef8998bca60998a1f2ec095434a6.
Revert "Revert "cpu boost: backport missing functions from 3.4""

This reverts commit 023146b8169f762adefcd0d8f5ec7fdc2d0798fd.