When PERF_COUNT_SW_BPF_OUTPUT was added to the kernel we should've
added it to tools/perf, where it is used just to list events.

This ended up causing a segfault in commands like "perf list stall".

Fix it by adding that new software counter.

A patch to robustify perf to not segfault when the next counter gets
added in the kernel will follow this one.
Reported-by: NIngo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-uya354upi3eprsey6mi5962d@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>