Version bump to NZH54B

Change-Id: Iebb6d3ebfd34f9f439f2b32bf080b74d1f7686c2
diff --git a/core/build_id.mk b/core/build_id.mk
index ba857dc..12340cc 100644
--- a/core/build_id.mk
+++ b/core/build_id.mk
@@ -18,4 +18,4 @@
 # (like "CRB01").  It must be a single word, and is
 # capitalized by convention.
 
-export BUILD_ID=NZH54
+export BUILD_ID=NZH54B