perf test: Use generic event for expand_libpfm_events()

I found that the UNHALTED_CORE_CYCLES event is only available in the
Intel machines and it makes other vendors/archs fail on the test.  As
libpfm4 can parse the generic events like cycles, let's use them.

Fixes: 40b74c30 ("perf test: Add expand cgroup event test")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201027072855.655449-1-namhyung@kernel.org


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