fix comments

Change-Id: I8312c8404edafd6a3807d02abe1b578b33479ccf
diff --git a/common/Makefile b/common/Makefile
index de6ffa0..34ee768 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -1,3 +1,5 @@
+# common/Makefile
+
 include $(COMMON_DIR)/Makedefs
 
 # prerequisite software