perf intel-pt: Record when decoding PSB+ packets

In preparation for using MTC packets to count cycles, record whether
decoding is between a PSB and PSBEND packets.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190520113728.14389-10-adrian.hunter@intel.com


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