perf test cs-etm: Replace unroll loop thread with deterministic decode test

perf test cs-etm: Replace unroll loop thread with deterministic decode test

Testing a long sequence without branches seems like it would be better
as a decoder unit test, and this test doesn't test decoding either, so
it's not clear what bugs this is trying to catch.

The new deterministic workload has somewhat long sequences when built
unoptimized, and we can always increase them later if we want to. But
now we test that decoding always gives the same result for the same
sequence of code which we've never had before.

Signed-off-by: James Clark <james.clark@linaro.org>
Tested-by: Leo Yan <leo.yan@arm.com>
Cc: Amir Ayupov <aaupov@meta.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Leach <mike.leach@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>