perf test: Parse 'perf stat' Topdown events for aarch64

The 'perf stat' output on aarch64 machines with topdown events wasn't
counted for in the 'perf stat STD output linter' test case. Add the
topdown metric to the skip_metric list as it is done for topdown events
on other systems.

The Topdown events are also disabled on aarch64 KVM guests because the
value of caps/slots is set to 0 due to the part of the system register
being a stub.

This prevents the metric for the topdown events from being computed,
leaving the 'perf stat' topdown metric without any value at all.

Add the "TopdownL1" to the skip_metric list as well to handle this
possibility.

Before aarch64:

    100: perf stat STD output linter:
    --- start ---
    test child forked, pid 403305
    Checking STD output: no args Unknown event name in TopdownL1   #      4.3 percent of slots  slots_lost_misspeculation_fraction
    ---- end(-1) ----
    100: perf stat STD output linter                             : FAILED!

Before aarch64 KVM:

    100: perf stat STD output linter:
    --- start ---
    test child forked, pid 404671
    Checking STD output: no args Unknown event name in TopdownL1
    ---- end(-1) ----
    100: perf stat STD output linter                             : FAILED!

After:

    100: perf stat STD output linter:
    --- start ---
    test child forked, pid 404777
    Checking STD output: no args [Success]
    Checking STD output: system wide [Success]
    Checking STD output: interval [Success]
    Checking STD output: per thread [Success]
    Checking STD output: per node [Success]
    Checking STD output: system wide no aggregation [Success]
    Checking STD output: per core [Success]
    Checking STD output: per cache instance [Success]
    Checking STD output: per cluster [Success]
    Checking STD output: per die [Success]
    Checking STD output: per socket [Success]
    ---- end(0) ----
    100: perf stat STD output linter                                     : Ok

Signed-off-by: Veronika Molnarova <vmolnaro@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20241029144347.25651-1-vmolnaro@redhat.com


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