perf data: Add tracepoint events fields CTF conversion support

Adding support to convert tracepoint event fields into CTF
event fields.

We parse each tracepoint event for CTF conversion and add
tracepoint fields as regular CTF event fields, so they
appear in babeltrace output like:

  $ babeltrace ./ctf-data/
  ...
  [09:02:00.950703057] (+?.?????????) sched:sched_stat_runtime: { }, { perf_ip = ... SNIP ... common_type = 298, common_flags = 1, \
  common_preempt_count = 0, common_pid = 31813, comm = "perf", pid = 31813, runtime = 458800, vruntime = 52059858071 }
  ...

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1424470628-5969-6-git-send-email-jolsa@kernel.org


Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>