perf cs-etm: Properly deal with cpu maps

perf cs-etm: Properly deal with cpu maps

This patch allows the CoreSight AUX info section to fit topologies where
only a subset of all available CPUs are present, avoiding at the same
time accessing the ETM configuration areas of CPUs that have been
offlined.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1518478737-24649-1-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>