tools build: Don't show libbfd build status as it is opt-in

tools build: Don't show libbfd build status as it is opt-in

Since dd317df072071903 ("perf build: Make binutil libraries opt in")
doesn't try to build with binutils libraries, so showing that it is OFF
when building causes just distraction, remove it from FEATURES_DISPLAY.

For people that for some reason notice that there is always 'perf -vv',
a short hand for 'perf version --build-options' and 'perf check feature
libbfd' that now explains why it is not built:

  $ perf check feature libbfd
  libbfd: [ OFF ]  # HAVE_LIBBFD_SUPPORT ( tip: Deprecated, license incompatibility, use BUILD_NONDISTRO=1 and install binutils-dev[el] )
  $

Fixes: dd317df072071903 ("perf build: Make binutil libraries opt in")
Tested-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/Z--pWmTHGb62_83e@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>