cosmetic: gprs_sgsn.c: move pdp.h include to top

Change-Id: I9a9b34d714235462ba72cdb65b7c8c9824dfa9c6
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index 038e6f0..9cd992b 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -40,6 +40,8 @@
 #include <openbsc/signal.h>
 #include "openbsc/gprs_llc.h"
 
+#include <pdp.h>
+
 #include <time.h>
 
 #include <openssl/rand.h>
@@ -337,7 +339,6 @@
 	return pdp;
 }
 
-#include <pdp.h>
 /*
  * This function will not trigger any GSM DEACT PDP ACK messages, so you
  * probably want to call sgsn_delete_pdp_ctx() instead if the connection