perf stat,jevents: Introduce Default tags for the default mode

perf stat,jevents: Introduce Default tags for the default mode

Introduce a new metricgroup, Default, to tag all the metric groups which
will be collected in the default mode.

Add a new field, DefaultMetricgroupName, in the JSON file to indicate
the real metric group name. It will be printed in the default output
to replace the event names.

There is nothing changed for the output format.

On SPR, both TopdownL1 and TopdownL2 are displayed in the default
output.

On ARM, Intel ICL and later platforms (before SPR), only TopdownL1 is
displayed in the default output.

Suggested-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ahmad Yasin <ahmad.yasin@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230615135315.3662428-4-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>