perf tests tsc: Add checking helper is_supported()

So far tsc is enabled on x86_64, i386 and Arm64 architectures, add
checking helper to skip this testing for other architectures.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20201019100236.23675-3-leo.yan@linaro.org


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