Package C2 residency counter is also available on Sierra Forest.
So add it support in srf_cstates.

Fixes: 3877d55a ("perf/x86/intel/cstate: Add Sierra Forest support")
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Wendy Wang <wendy.wang@intel.com>
Link: https://lore.kernel.org/r/20240717031609.74513-1-zhenyuw@linux.intel.com