thermal-service: Implement stalled fan/RPM mismatch detection

[kurtjd]

A fan could stall or misbehave in other ways (such as speeding up beyond what it was told to). Implement a way to detect this (such as comparing measured RPM to requested RPM) and handle it such as generating an event and/or throttling AP (such as in the case of stalled fan) as a fail-safe mechanism.