Backport 2.1:Add configuration file in md.h

include `*config.h*` in md.h as MACROS in the header file get ignored.
Fix for #1001.
diff --git a/ChangeLog b/ChangeLog
index 1d06476..67376cf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+
+= mbed TLS x.x.x branch released xxxx-xx-xx
+
+Bugfix
+   * Include configuration file in md.h, to fix compilation warnings.
+     Reported by aaronmdjones in #1001
+     
 = mbed TLS 2.1.9 branch released 2017-08-10
 
 Security