perf tests: Add attr record group sampling test

perf tests: Add attr record group sampling test

Adding test to validate perf_event_attr data for command:

  'record -e '{cycles,cache-misses}:S'

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-9eppxvhkly6gse5ximudckrp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>