fs/resctrl: Move allocation/free of closid_num_dirty_rmid[]

fs/resctrl: Move allocation/free of closid_num_dirty_rmid[]

closid_num_dirty_rmid[] and rmid_ptrs[] are allocated together during resctrl
initialization and freed together during resctrl exit.

Telemetry events are enumerated on resctrl mount so only at resctrl mount will
the number of RMID supported by all monitoring resources and needed as size
for rmid_ptrs[] be known.

Separate closid_num_dirty_rmid[] and rmid_ptrs[] allocation and free in
preparation for rmid_ptrs[] to be allocated on resctrl mount.

Keep the rdtgroup_mutex protection around the allocation and free of
closid_num_dirty_rmid[] as ARM needs this to guarantee memory ordering.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com