[REPOST PATCH v3] powerpc/papr_scm: Move duplicate definitions to common header files

papr_scm and ndtest share common PDSM payload structs like nd_papr_pdsm_health. Presently these structs are duplicated across papr_pdsm.h and ndtest.h header files. Since 'ndtest' is essentially arch independent and can run on platforms other than PPC64, a way needs to be deviced to avoid

[REPOST PATCH v3] powerpc/papr_scm: Move duplicate definitions to common header files

papr_scm and ndtest share common PDSM payload structs like nd_papr_pdsm_health. Presently these structs are duplicated across papr_pdsm.h and ndtest.h header files. Since 'ndtest' is essentially arch independent and can run on platforms other than PPC64, a way needs to be deviced to avoid