perf report: Add --percent-type option

Set annotation percent type from following choices:

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

With following report option setup the percent type will be passed to
annotation browser:

  $ perf report --percent-type period-local

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/20180804130521.11408-21-jolsa@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>