FeaturePerfMon relates to the PMU extensions available in armv7-a, and should not be available in v7-m (it requires loading from a system register with a mrc). Sink it down a level in the dependency map so that it isn't present in ARMv7m or HasV8MMainlineOps.
It is also removed from the Neoverse-N2, as it will already be transitively included.