Add --percent-type option to set annotation percent type from following
choices:

  global-period, local-period, global-hits, local-hits

Examples:

  $ perf annotate --percent-type period-local --stdio | head -1
   Percent         |      Source code ... es, percent: local period)
  $ perf annotate --percent-type hits-local --stdio | head -1
   Percent         |      Source code ... es, percent: local hits)
  $ perf annotate --percent-type hits-global --stdio | head -1
   Percent         |      Source code ... es, percent: global hits)
  $ perf annotate --percent-type period-global --stdio | head -1
   Percent         |      Source code ... es, percent: global period)

The local/global keywords set if the percentage is computed in the scope
of the function (local) or the whole data (global).

The period/hits keywords set the base the percentage is computed on -
the samples period or the number of samples (hits).
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20180804130521.11408-20-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>