perf evsel: Provide meaningful warning when trying to use 'aux_output' on older kernels

Just like we do with the 'write_backwards' feature:

Before:

  # perf record -e {intel_pt/branch=0/,cycles/aux-output/ppp} uname
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cycles/aux-output/ppp).
  /bin/dmesg | grep -i perf may provide additional information.

  #

After:

  # perf record -e {intel_pt/branch=0/,cycles/aux-output/ppp} uname
  Error:
  The 'aux_output' feature is not supported, update the kernel.
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.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://lkml.kernel.org/n/tip-wgjsjroe1e150c0metgwmqwd@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evsel.h

@@ -184,6 +184,7 @@ struct perf_missing_features {
 	bool group_read;
 	bool ksymbol;
 	bool bpf_event;
+	bool aux_output;
 };
 
 extern struct perf_missing_features perf_missing_features;