PRD: FFDC registers for channel failure attentions

Change-Id: Ibe00ac2ac20fc93a4783070cda66f1f63fccf1a4
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/59715
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: Matt Derksen <mderkse1@us.ibm.com>
Reviewed-by: Benjamin J. Weisenbeck <bweisenb@us.ibm.com>
Reviewed-by: Zane C. Shelley <zshelle@us.ibm.com>
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/59765
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>

src/usr/diag/prdf/common/plat/p9/p9_mc_regs.rule

@@ -39,3 +39,14 @@
         access      write_only;
     };
 
+    ############################################################################
+    # Config registers for channel failure attentions
+    ############################################################################
+
+    register SCOM_MODE_PB
+    {
+        name        "IOMP.BUSCTL.SCOM.SCOM_MODE_PB";
+        scomaddr    0x07011020;
+        capture     group default;
+    };
+