perf tools: Add processing of coresight metadata

The auxtrace_info section contains metadata that describes the number of
trace capable CPUs, their ETM version and trace configuration, including
trace id values. This information is required by the trace decoder in
order to properly decode the compressed trace packets. This patch adds
code to read and parse this metadata, and store it for use in
configuring instances of the cs-etm trace decoder.

Co-authored-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Tor Jeremiassen <tor@ti.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Mike Leach <mike.leach@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1516211539-5166-4-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>