cpufreq: schedutil: Add cpu_frequency traces for each cpu in the policy

Add cpu_frequency traces for each online CPU in the policy for more
consistent outputs of most standard trace analysis tools.

Change-Id: I01cd48909316f861cb601c2ce74330351320f1b5
Signed-off-by: Kyle Yan <kyan@codeaurora.org>
[avilaj@codeaurora.org: Port to 4.19, fix conflicts]
Signed-off-by: Jonathan Avila <avilaj@codeaurora.org>