Make use of user/system includes more consistent

Make codebase consistent in its use of #include "" syntax for
user includes and #include <> syntax for system includes.

Fixes ARM-software/tf-issues#65

Change-Id: If2f7c4885173b1fd05ac2cde5f1c8a07000c7a33
diff --git a/services/spd/tspd/tspd_main.c b/services/spd/tspd/tspd_main.c
index 543266e..90fa094 100644
--- a/services/spd/tspd/tspd_main.c
+++ b/services/spd/tspd/tspd_main.c
@@ -49,9 +49,9 @@
 #include <bl31.h>
 #include <tsp.h>
 #include <psci.h>
-#include <tspd_private.h>
 #include <debug.h>
 #include <uuid.h>
+#include "tspd_private.h"
 
 /*******************************************************************************
  * Single structure to hold information about the various entry points into the