Revert "perf parse-events: Prefer sysfs/JSON hardware events over legacy"

This reverts commit 617824a7

.

This made a simple 'perf record -e cycles:pp make -j199' stop working on
the Ampere ARM64 system Linus uses to test ARM64 kernels, as discussed
at length in the threads in the Link tags below.

The fix provided by Ian wasn't acceptable and work to fix this will take
time we don't have at this point, so lets revert this and work on it on
the next devel cycle.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Cc: Ethan Adams <j.ethan.adams@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Tycho Andersen <tycho@tycho.pizza>
Cc: Yang Jihong <yangjihong@bytedance.com>
Link: https://lore.kernel.org/lkml/CAHk-=wi5Ri=yR2jBVk-4HzTzpoAWOgstr1LEvg_-OXtJvXXJOA@mail.gmail.com
Link: https://lore.kernel.org/lkml/CAHk-=wiWvtFyedDNpoV7a8Fq_FpbB+F5KmWK2xPY3QoYseOf_A@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>