properly #include <openbsc/gsm_data.h> from gsm_subscriber.h

Don't use quoted, local include, use <> style include.

Cosmetic: also move stdbool.h include to the top to keep osmocom and openbsc
includes grouped.

Change-Id: Iaa3dc36768f96f6b8c91010a2ba389fdc37f1503
diff --git a/openbsc/include/openbsc/gsm_subscriber.h b/openbsc/include/openbsc/gsm_subscriber.h
index 3d7c244..314d619 100644
--- a/openbsc/include/openbsc/gsm_subscriber.h
+++ b/openbsc/include/openbsc/gsm_subscriber.h
@@ -1,11 +1,12 @@
 #ifndef _GSM_SUBSCR_H
 #define _GSM_SUBSCR_H
 
-#include "gsm_data.h"
+#include <stdbool.h>
+
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/gsm/protocol/gsm_23_003.h>
 
-#include <stdbool.h>
+#include <openbsc/gsm_data.h>
 
 #define GSM_NAME_LENGTH 160