perf intel-pt: Add CBR value to decoder state

For convenience, add the core-to-bus ratio (CBR) value to the decoder
state.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190622093248.581-4-adrian.hunter@intel.com


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