IRK21B

Change-Id: Id0f5bc955d6adbb960be5119b196a5a0ca68e0f1
diff --git a/core/build_id.mk b/core/build_id.mk
index 6a6ebf9..6798916 100644
--- a/core/build_id.mk
+++ b/core/build_id.mk
@@ -19,4 +19,4 @@
 # (like "CRB01").  It must be a single word, and is
 # capitalized by convention.
 
-export BUILD_ID=IRK21
+export BUILD_ID=IRK21B