perf stat record: Save cache level information

perf stat record: Save cache level information

When aggregating based on cache-topology, in addition to the aggregation
mode, knowing the cache level at which data is aggregated is necessary
to ensure consistency when running 'perf stat record' and later 'perf
stat report'.

Save the cache level for aggregation as a part of the env data that can
be later retrieved when running perf stat report.

Suggested-by: Gautham Shenoy <gautham.shenoy@amd.com>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wen Pu <puwen@hygon.cn>
Link: https://lore.kernel.org/r/20230517172745.5833-4-kprateek.nayak@amd.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>