shift OBUS FIR programming inits for secure boot

p9_sbe_scominit:
unmask all OBUS EXTFIR bits, use PB CENT FIR 14 to mark update
for downstream code (qualify XBUS/OBUS EXTFIR updates to apply to PPE
platform only)

p9_fab_iovalid:
conditionally unmask OBUS EXTFIR based on state of PB CENT FIR 14
(will handle unmasking here when insecure -- Cronus or old SBE images)

p9_obus_extfir_setup:
new HWP for HB to call, mask OBUS EXTFIR bits for unused busses

Change-Id: I07e7da4a7c61c041451ff4ddfeec3c266385d404
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/60358
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: HWSV CI <hwsv-ci+hostboot@us.ibm.com>
Tested-by: PPE CI <ppe-ci+hostboot@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: Thi N. Tran <thi@us.ibm.com>
Reviewed-by: Sachin Gupta <sgupta2m@in.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/60363
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/import/chips/p9/procedures/hwp/nest/p9_fab_iovalid.C

@@ -890,7 +890,8 @@ p9_fab_iovalid_update_link(const fapi2::Target<fapi2::TARGET_TYPE_PROC_CHIP>& i_
                  "Error from getScom (PU_PB_CENT_SM0_PB_CENT_FIR_REG)");
 
         // clear RAS FIR mask for optical link, or electrical link if not already setup by SBE
-        if ((i_ctl.endp_type == OPTICAL) ||
+        if (((i_ctl.endp_type == OPTICAL) &&
+             (!l_fbc_cent_fir_data.getBit<PU_PB_CENT_SM0_PB_CENT_FIR_MASK_REG_SPARE_14>())) ||
             ((i_ctl.endp_type == ELECTRICAL) &&
              (!l_fbc_cent_fir_data.getBit<PU_PB_CENT_SM0_PB_CENT_FIR_MASK_REG_SPARE_13>())))
         {