Revert "cpufreq: interactive: remove input_boost handling"

since we removed powerhal, which is a pretty big part of google's so-called project butter, it's time to bring this back.

This reverts commit 4e27eb56e819745a1b184f278d7f3dd3887a456c.

Change-Id: I438a7694852b40566891975054f4095ea8f09680