[FEATURE] report backtraces and warnings as errors

[plbossart]

Is your feature request related to a problem? Please describe.

thesofproject/linux#3362 describes a case where there are at least 3 developers reproducing a problem we have not seen in CI.

This could be due to the fact that 'warnings' are not trapped by our scripts, or that somehow we have not tested in the same condition. I will assume it's the former case for now.

Describe the solution you'd like

We can have different levels:

report backtraces as errors and filter if the issues are not due to SOF
report all warnings and filter if the issues are not due to SOF

Describe alternatives you've considered
I don't see any.

Additional context
Our CI/validation will not be trusted if we end-up polluting the mainline kernel with warnings that are not detected. This is not a drill, we need to fix this.

[plbossart]

Adding kernel maintainers for feedback @kv2019i @ujfalusi @ranj063 @bardliao

[bardliao]

I vote for the first level. ie. report backtraces as errors and filter if the issues are not due to SOF.
People don't like to see any backtraces. Regarding warnings, I am wondering how many warnings will be seen with current code base. We may filter the issues not due to SOF, but I can expect that we will often see new warnings after doing upstream merge.