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

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/6648

JIRA: https://issues.redhat.com/browse/RHEL-78426

In RHEL 9 running the "perf stat STD output linter" test fails:

```
 91: perf stat STD output linter:
--- start ---
test child forked, pid 648531
Checking STD output: no args Unknown event name in TopdownL1                 #      2.5 percent of slots  slots_lost_misspeculation_fraction
---- end(-1) ----
 91: perf stat STD output linter                                     : FAILED!
```

This MR adds TopdownL1 to the list of skipped metrics in the test.

Signed-off-by: Anubhav Shelat <ashelat@redhat.com>

Approved-by: Michael Petlan <mpetlan@redhat.com>
Approved-by: Tony Camuso <tcamuso@redhat.com>
Approved-by: jbrnak <jbrnak@redhat.com>
Approved-by: Jarod Wilson <jarod@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Augusto Caringi <acaringi@redhat.com>

Author: caringi

tools/perf/tests/shell/stat+std_output.sh

@@ -13,7 +13,7 @@ stat_output=$(mktemp /tmp/__perf_test.stat_output.std.XXXXX)
 
 event_name=(cpu-clock task-clock context-switches cpu-migrations page-faults stalled-cycles-frontend stalled-cycles-backend cycles instructions branches branch-misses)
 event_metric=("CPUs utilized" "CPUs utilized" "/sec" "/sec" "/sec" "frontend cycles idle" "backend cycles idle" "GHz" "insn per cycle" "/sec" "of all branches")
-skip_metric=("stalled cycles per insn" "tma_" "retiring" "frontend_bound" "bad_speculation" "backend_bound")
+skip_metric=("stalled cycles per insn" "tma_" "retiring" "frontend_bound" "bad_speculation" "backend_bound" "TopdownL1" "percent of slots")
 
 cleanup() {
   rm -f "${stat_output}"