ANDROID: cpufreq: schedutil: drop cache when update skipped due to rate limit

When frequency limits changed faster than sugov_up_down_rate_limit
permits, the frequency change will be ignored. When a demanding workload
runs with thermal governor which adjusts limits frequently and frequency
relax action missed, the thermal governor will happy to settle (no
further update on limit as thermal condition is maintained). So there
won't be any new limits change. As workload continues to occupy the CPU,
the votes from scheduler is all not updated. All these leads to a
situation where the workload stuck at a low frequency until quits.

If a frequency change is dropped due to rate limit, we should drop the
cache. Besides the above mentioned limits changed case, there are also
other cases when frequency update could be dropped.

Bug: 159936782
Bug: 158863204
Signed-off-by: Wei Wang <wvw@google.com>
Change-Id: I9db69cd3e03f949cfe9a9a416fd33eea3907deec