perf vendor events power9: Add hv_24x7 core level metric events

This patch adds hv_24x7 core level events in nest_metric.json file and
also add PerChip/PerCore field in metric events.

Result:

power9 platform:

command:# ./perf stat --metric-only -M PowerBUS_Frequency -C 0 -I 1000
     1.000070601                        1.9                        2.0
     2.000253881                        2.0                        1.9
     3.000364810                        2.0                        2.0

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20200907064133.75090-6-kjain@linux.ibm.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>