simpleperf: add cs-etm event type.

cs-etm event type is used to select etm instruction tracing.
It can be show in simpleperf list cmd, and used by
`simpleperf record -e cs-etm`.

Changes receiving etm data from the kernel will be added
in later CLs.

Bug: 135204414
Test: run simpleperf_unit_test.
Change-Id: I431b5521dc23519ff8e154d50458ec0aa9ac65cd
8 files changed