perf json: Add s390 transaction counter definition

perf json: Add s390 transaction counter definition

'perf stat' displays transactional counters using flag -T on x86.  On
s390 use a JSON file defined metric named transaction to achieve the
same result.

Output before:

  none

Output after:

  [root@s35lp76 perf]# ./perf stat -M transaction  -- \
			  ~/mytesttx 1 >/tmp/111

   Performance counter stats for '/root/mytesttx 1':

                   1      tx_c_tend           #     13.0 transaction
                   1      tx_nc_tend
                  11      tx_nc_tabort
                   0      tx_c_tabort_special
                   0      tx_c_tabort_no_special

         0.001061232 seconds time elapsed

  [root@s35lp76 perf]#

Suggested-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180621080452.61012-3-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>