Some cstate counters become die-scoped on Xeon Cascade Lake-AP. Perf cstate
driver needs to support die-scope cstate counters.

Use topology_die_cpumask() to replace topology_core_cpumask().  For
previous platforms which doesn't have multi-die, topology_die_cpumask() is
identical as topology_core_cpumask().  There is no functional change for
previous platforms.

Name the die-scope PMU "cstate_die".
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/acb5e483287280eeb2b6daabe04a600b85e72a78.1557769318.git.len.brown@intel.com