perf tools: Implement branch_type event parameter

perf tools: Implement branch_type event parameter

It can be useful to specify branch type state per event, for example if
we want to collect both software trace points and last branch PMU events
in a single collection. Currently this doesn't work because the software
trace point errors out with -b.

There was already a branch-type parameter to configure branch sample
types per event in the parser, but it was stubbed out. This patch
implements the necessary plumbing to actually enable it.

Now:

  $ perf record -e sched:sched_switch,cpu/cpu-cycles,branch_type=any/ ...

works.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1476306127-19721-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>