Add PMIC enable procedure code and UTs

Change-Id: I46ab8808d535acba4f88926f25e66c5b276bef2b
Original-Change-Id: Iac5cd8016efa705be6512b842e0e793eb3d4c5fa
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/74639
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Tested-by: HWSV CI <hwsv-ci+hostboot@us.ibm.com>
Reviewed-by: Louis Stermole <stermole@us.ibm.com>
Reviewed-by: STEPHEN GLANCY <sglancy@us.ibm.com>
Reviewed-by: Thi N. Tran <thi@us.ibm.com>

src/import/generic/memory/lib/utils/shared/mss_generic_consts.H

@@ -180,6 +180,7 @@ enum generic_ffdc_codes
     SET_DIMM_RANKS_CNFG = 0x1039,
     DDIMM_RAWCARD_DECODE = 0x103a,
     INIT_RANK_INFO = 0x103B,
+    BIAS_PMIC_FROM_SPD = 0x103C,
     SET_DRAM_WIDTH = 0x1040,
 
     SET_SI_VREF_DRAM_WR = 0x1041,