perf, sparc: Implement group scheduling transactional APIs

Convert to the transactional PMU API and remove the duplication of
group_sched_in().

[cross build only]

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Acked-by: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1272002193.5707.65.camel@minggr.sh.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>