Add new P9A hwp error xml path to fapi2 file generation makefile

In fapi2.mk we run a lot of scripts which generate various headers
based upon information we parse for different XML files. We were
missing the new path of XML files that was added for Axone and
this commit addresses that.

Change-Id: I2815221483a71d62120503b35feaa5c719cc8866
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/71943
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Roland Veloz <rveloz@us.ibm.com>
Reviewed-by: Matt Derksen <mderkse1@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/usr/fapi2/fapi2.mk

@@ -5,7 +5,7 @@
 #
 # OpenPOWER HostBoot Project
 #
-# Contributors Listed Below - COPYRIGHT 2015,2018
+# Contributors Listed Below - COPYRIGHT 2015,2019
 # [+] International Business Machines Corp.
 #
 #
@@ -125,6 +125,8 @@ FAPI2_ERROR_XML += $(wildcard \
   $(ROOTPATH)/src/import/generic/procedures/xml/error_info/*.xml)
 FAPI2_ERROR_XML += $(wildcard \
   $(ROOTPATH)/src/import/chips/ocmb/explorer/procedures/xml/error_info/*.xml)
+FAPI2_ERROR_XML += $(wildcard \
+  $(ROOTPATH)/src/import/chips/p9a/procedures/xml/error_info/*.xml)
 
 # Attribute XML files.
 FAPI2_ATTR_XML += $(wildcard \