Update security string to 2016-09-07 to platform and CTS for September   respin am: cc5148493f
am: 637fa9c4c5

Change-Id: I8f5459266c69eddf11101f9be3a46beecdc71dad
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 94c250d..77064c0 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -68,7 +68,7 @@
   # Can be an arbitrary string, but must be a single word.
   #
   # If there is no $PLATFORM_SECURITY_PATCH set, keep it empty.
-  PLATFORM_SECURITY_PATCH := 2016-09-05
+  PLATFORM_SECURITY_PATCH := 2016-09-07
 endif
 
 ifeq "" "$(PLATFORM_BASE_OS)"