L1CTL_Types: Split t_IMM_ASS() off t_RR_IMM_ASS()

It's useful to have a separat template only for the IM_ASS part, without
RR header.
diff --git a/library/L1CTL_Types.ttcn b/library/L1CTL_Types.ttcn
index 4b68c61..f687c95 100644
--- a/library/L1CTL_Types.ttcn
+++ b/library/L1CTL_Types.ttcn
@@ -501,18 +501,21 @@
 		}
 	};
 
-	template GsmRrMessage t_RR_IMM_ASS(uint8_t ra, uint8_t fn) := {
+	template ImmediateAssignment t_IMM_ASS(uint8_t ra, GsmFrameNumber fn) := {
+		ded_or_tbf := ?,
+		page_mode := ?,
+		chan_desc := *,
+		pkt_chan_desc := *,
+		req_ref := f_compute_ReqRef(ra, fn),
+		timing_advance := ?,
+		mobile_allocation := ?,
+		rest_octets:= ?
+	};
+
+	template GsmRrMessage t_RR_IMM_ASS(uint8_t ra, GsmFrameNumber fn) := {
 		header := t_RrHeader(IMMEDIATE_ASSIGNMENT, ?),
 		payload := {
-			imm_ass := {
-				ded_or_tbf := ?,
-				page_mode := ?,
-				chan_desc := *,
-				pkt_chan_desc := *,
-				req_ref := f_compute_ReqRef(ra, fn),
-				timing_advance := ?,
-				mobile_allocation := ?
-			}
+			imm_ass := t_IMM_ASS(ra, fn)
 		}
 	};