simpleperf: add --trace-offcpu option to scripts.

Add --trace-offcpu option to set trace-offcpu report mode
in inferno.py, report_html.py and report_sample.py.

Bug: 38383695
Test: run scripts/test/test.py --only-host-test
Change-Id: I639fd54e87dfdb330f5945c9aeafa42cda73e170
7 files changed