Handle multi-step operator's profile data (#2414)

Handle multi-step operator's profile data (#2414)

- Add profiler_summarizer in tools/tfite_benchmark_model

profile_summarizer must understand multi-step expansion for
pureACL runtime. So I need to introduce our own profiler_summarizer
which is based on original tflite_benchmark_model's profiler_summarizer.

- Handle multi-step operator's profile data

Now, it can handle multi step expanded operators.

The only modifications are in profile_summarizer.cc's ProcessProfiles().
You can do diff with tensorflow-v1.9.0-rc2.

Related Issue: #2376, #1696

Signed-off-by: Sanggyu Lee <sg5.lee@samsung.com>