perf/x86/rapl: Clean up cpumask and hotplug

The rapl pmu is die scope, which is supported by the generic perf_event
subsystem now.

Set the scope for the rapl PMU and remove all the cpumask and hotplug
codes.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Oliver Sang <oliver.sang@intel.com>
Tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Link: https://lore.kernel.org/r/20241010142604.770192-2-kan.liang@linux.intel.com