Clean up more warnings in lk code

Change-Id: I71eb3f1730ae0c80ec4d0da12a5b5755bc9f5614
diff --git a/platform/msm_shared/mddi.c b/platform/msm_shared/mddi.c
index b8a519b..173ea34 100644
--- a/platform/msm_shared/mddi.c
+++ b/platform/msm_shared/mddi.c
@@ -34,6 +34,7 @@
 #include <kernel/thread.h>
 #include <mddi.h>
 #include <target/display.h>
+#include <platform/timer.h>
 
 #include "mddi_hw.h"