powerpc/papr_scm: Add perf interface support

Performance monitoring support for papr-scm nvdimm devices
via perf interface is added which includes addition of pmu
functions like add/del/read/event_init for nvdimm_pmu struture.

A new parameter 'priv' in added to the pdev_archdata structure to save
nvdimm_pmu device pointer, to handle the unregistering of pmu device.

papr_scm_pmu_register function populates the nvdimm_pmu structure
with name, capabilities, cpumask along with event handling
functions. Finally the populated nvdimm_pmu structure is passed to
register the pmu device. Event handling functions internally uses
hcall to get events and counter data.

Result in power9 machine with 2 nvdimm device:

Ex: List all event by perf list

command:# perf list nmem

  nmem0/cache_rh_cnt/                                [Kernel PMU event]
  nmem0/cache_wh_cnt/                                [Kernel PMU event]
  nmem0/cri_res_util/                                [Kernel PMU event]
  nmem0/ctl_res_cnt/                                 [Kernel PMU event]
  nmem0/ctl_res_tm/                                  [Kernel PMU event]
  nmem0/fast_w_cnt/                                  [Kernel PMU event]
  nmem0/host_l_cnt/                                  [Kernel PMU event]
  nmem0/host_l_dur/                                  [Kernel PMU event]
  nmem0/host_s_cnt/                                  [Kernel PMU event]
  nmem0/host_s_dur/                                  [Kernel PMU event]
  nmem0/med_r_cnt/                                   [Kernel PMU event]
  nmem0/med_r_dur/                                   [Kernel PMU event]
  nmem0/med_w_cnt/                                   [Kernel PMU event]
  nmem0/med_w_dur/                                   [Kernel PMU event]
  nmem0/mem_life/                                    [Kernel PMU event]
  nmem0/poweron_secs/                                [Kernel PMU event]
  ...
  nmem1/mem_life/                                    [Kernel PMU event]
  nmem1/poweron_secs/                                [Kernel PMU event]

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
[Add numa_map_to_online_node function call to get online node id]
Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@in.ibm.com>
Link: https://lore.kernel.org/r/20220225143024.47947-4-kjain@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>