libpmc: add some AMD pmu counter aliases

[mhorne]

Summary

Make it mostly compatible with what's defined for Intel. Except where
noted, these are defined for all of amdzen(1|2|3).

[emaste]

lib/libpmc/libpmc_pmu_util.c

97

where does this one come from?

[mhorne]

lib/libpmc/libpmc_pmu_util.c

97

It is meant to invoke the pmc.tsc(3) class, which has exactly one event that reads the TSC. I copied it from the Intel aliases above, but looking at it now, this doesn't actually work...

I will move this alias out of this file to a more appropriate place.

[mhorne]

Drop non-functional 'cycles' alias in favor of D32197.