Add option to remove GUARD partition on PNOR update

Change-Id: If3e854f97485dcab3efa59e41fda6a735762645c
Signed-off-by: Charles Paul Hofer <Charles.Hofer@ibm.com>
diff --git a/lib/resource.txt b/lib/resource.txt
index 8f00efb..45049bc 100755
--- a/lib/resource.txt
+++ b/lib/resource.txt
@@ -57,9 +57,10 @@
 ${BMC_IMAGE_FILE_PATH}          ${EMPTY}
 ${BAD_IMAGES_DIR_PATH}          ${EMPTY}
 
-# The caller must set this to the string "true" in order to delete images. The
-# code is picky.
+# The caller must set this to the string "true" in order to delete images or
+# the GUARD file. The code is picky.
 ${DELETE_OLD_PNOR_IMAGES}   false
+${DELETE_OLD_GUARD_FILE}    true
 
 # Caller can specify a value for LAST_KNOWN_GOOD_VERSION to indicate that if
 # the machine already has that version on it, the update should be skipped.