ns2: move link layer type into NSE

Even it was in theory possible to mix NS-VC ll types within
a NSE. This is an unrealistic configuration.
Further more to select the correct load sharing mechanism
the NSE must know the correct link layer.

Change-Id: I18dfd40a2429cd61b7c4a3dad5f226c64296f7d8
diff --git a/src/gb/gprs_ns2_internal.h b/src/gb/gprs_ns2_internal.h
index d7211e5..08ffac2 100644
--- a/src/gb/gprs_ns2_internal.h
+++ b/src/gb/gprs_ns2_internal.h
@@ -123,6 +123,9 @@
 	/*! true if this NSE has at least one alive VC */
 	bool alive;
 
+	/*! which link-layer are we based on? */
+	enum gprs_ns2_ll ll;
+
 	struct osmo_fsm_inst *bss_sns_fi;
 };
 
@@ -164,8 +167,6 @@
 	struct rate_ctr_group *ctrg;
 	struct osmo_stat_item_group *statg;
 
-	/*! which link-layer are we based on? */
-	enum gprs_ns2_ll ll;
 	enum gprs_ns2_vc_mode mode;
 
 	struct osmo_fsm_inst *fi;
@@ -186,6 +187,9 @@
 	/*! if VCs use reset/block/unblock method. IP shall not use this */
 	enum gprs_ns2_vc_mode vc_mode;
 
+	/*! which link-layer are we based on? */
+	enum gprs_ns2_ll ll;
+
 	/*! send a msg over a VC */
 	int (*send_vc)(struct gprs_ns2_vc *nsvc, struct msgb *msg);