power-libperfmgr: Fix boost timer resetting stale timer

Currently the boost timer resets the stale timer when it turns off.
That's less than ideal, but this should fix it.

This also adds code to prevent multiple sequential boosts from re-using
uclamp.min values when calculating what to return to once the boost ends

Bug: 267385642
Bug: 267391322
Test: manual
Change-Id: I70d835f4add242c10788aa893fb2f49774e1a538
2 files changed