Version bump to SP1A.210812.016.B2 [core/build_id.mk]

Change-Id: Ia02dc20a1be4516cbc1e67d4b19acc27d5c1e0f8
diff --git a/core/build_id.mk b/core/build_id.mk
index cb659477..715af5e 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.
 
-BUILD_ID=SP1A.210812.016.B1
+BUILD_ID=SP1A.210812.016.B2