Draft: freedreno: missing a6xx performance counters, countables
This starts as a sort of RFC: there are some additional perfcounter groups as well as countables for existing groups that could be included.
Current changes:
- add a perfcounter group for the CMP hwblock,
- add additional PERF_UCHE countables,
- add additional PERF_SP countables.
There's other additional groups that could finally be added if they are of interest and functioning properly, e.g. for the RBBM and VBIF blocks.