perf cs-etm: Add last instruction information in packet

Decoder provides last instruction related information, these information
can be used for trace analysis; specifically we can get to know what
kind of branch instruction has been executed, mainly the information are
contained in three element fields:

  last_i_type: this is significant type for waypoint calculation, it
  indicates the last instruction is one of immediate branch instruction,
  indirect branch instruction, instruction barrier (ISB), or data
  barrier (DSB/DMB).

  last_i_subtype: this is used for instruction sub type, it can be
  branch with link, ARMv8 return instruction, ARMv8 eret instruction
  (return from exception), or ARMv7 instruction which could imply
  return (e.g. MOV PC, LR; POP { ,PC}).

  last_instr_cond: it indicates if the last instruction was conditional.

But these three fields are not saved into cs_etm_packet struct, thus
cs-etm layer don't know related information and cannot generate sample
flags for branch instructions.

This patch add corresponding three new fields in cs_etm_packet struct
and save related value into the packet structure, it is preparation for
supporting sample flags.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: Suzuki K Poulouse <suzuki.poulose@arm.com>
Cc: coresight ml <coresight@lists.linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190129122842.32041-2-leo.yan@linaro.org


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