arm64: pmu: Probe default hw/cache counters

ARMv8 machines can identify the micro/arch defined counters
that are available on a machine. Add all these counters to the
default armv8 perf map. At run-time disable the counters which
are not available on the given PMU.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>