perf: Extract building cache level for a CPU into separate function

build_caches() builds the complete cache topology of the system by
iterating over all CPU, building and comparing cache levels of each CPU,
keeping only the unique ones at the end.

Extract the unit that build the cache levels for a single CPU into a
separate function. Expose this function, and the MAX_CACHE_LVL value to
be used elsewhere in perf too.

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: Gautham Shenoy <gautham.shenoy@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/20230517172745.5833-2-kprateek.nayak@amd.com


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