Updated backing build in customrc

Change-Id: I28e49f266431efbc60ce813d07ac5ebd9ecc211f
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/88339
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: RAJA DAS <rajadas2@in.ibm.com>

customrc

@@ -33,6 +33,6 @@ export SANDBOXNAME=test_sb
 #export WORKSPACE=<set it to your root ppe directory. This is required if you
 #                  to use build script locally>
 export MACHINE=NIMBUS
-export BACKING_BUILD=/esw/fips940/Builds/b0729a_1931.940/
+export BACKING_BUILD=/esw/fips940/Builds/b1209a_1951.940/
 export SIMICSOPTIONS="-nre"
 export SIMICS_TAR=/gsa/ausgsa/projects/s/simics_published_builds/p10/973eb447cf3b9e7abbc173783d81ab25e3ff998a/