perf intel-pt: Add decoder support for PEBS via PT

PEBS data is encoded in Block Item Packets (BIP). Populate a new structure
intel_pt_blk_items with the values and, upon a Block End Packet (BEP),
report them as a new Intel PT sample type INTEL_PT_BLK_ITEMS.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190610072803.10456-4-adrian.hunter@intel.com


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