perf version: Add a feature for libpfm4

If perf is built with libpfm4 (LIBPFM4=1) then advertise it in perf -vv.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201019232545.4047264-1-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-version.c

@@ -80,6 +80,7 @@ static void library_status(void)
 	STATUS(HAVE_LIBBPF_SUPPORT, bpf);
 	STATUS(HAVE_AIO_SUPPORT, aio);
 	STATUS(HAVE_ZSTD_SUPPORT, zstd);
+	STATUS(HAVE_LIBPFM, libpfm4);
 }
 
 int cmd_version(int argc, const char **argv)