perf test: Skip CoreSight tests if cs_etm// event is not available

CoreSight might be not available, in such case, skip the tests.

Signed-off-by: Michael Petlan <mpetlan@redhat.com>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: vmolnaro@redhat.com
Link: https://lore.kernel.org/r/20231019091137.22525-1-mpetlan@redhat.com


Signed-off-by: Namhyung Kim <namhyung@kernel.org>