Fix bug with compatibility memory define/header
diff --git a/include/polarssl/config.h b/include/polarssl/config.h
index 41ca1ab..ad0cceb 100644
--- a/include/polarssl/config.h
+++ b/include/polarssl/config.h
@@ -1679,6 +1679,7 @@
 /**
  * \def POLARSSL_MEMORY_C
  * Deprecated since 1.3.5. Please use POLARSSL_PLATFORM_MEMORY instead.
+ * Depends on: POLARSSL_PLATFORM_C
  */
 //#define POLARSSL_MEMORY_C