Add support for reporting DIMM health and shutdown state by issuing
PAPR_SCM_PDSM_HEALTH request to papr_scm module. It returns an
instance of 'struct nd_papr_pdsm_health' as defined in
'papr_scm_pdsm.h'. The patch provides support for dimm-ops
'new_smart', 'smart_get_health' & 'smart_get_shutdown_state' as newly
introduced functions papr_new_smart_health(), papr_smart_get_health()
& papr_smart_get_shutdown_state() respectively. These callbacks should
enable ndctl to report DIMM health.

Also a new member 'struct dimm_priv.health' is introduced which holds
the current health status of the dimm. This member is set inside newly
added function 'update_dimm_health_v1()' which parses the v1 payload
returned by the kernel after servicing PAPR_SCM_PDSM_HEALTH. The
function will also update dimm-flags viz 'struct ndctl_dimm.flags.f_*'
based on the flags set in the returned payload.

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
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Changelog:

v1..v2:
* Squashed patch to report nvdimm bad shutdown state with this patch.
* Switched to new structs/enums as defined in papr_scm_pdsm.h