cosmetic: RLCMAC_Types.ttcn: Make different PTCCH types section more visible

On top there's a lot of types related to data blocks. Having more
stylish section header helps orientating one self while looking through
the data blocks.

Change-Id: I87d4694031ea6874b233626818824cdc4f3505c6
diff --git a/library/RLCMAC_Types.ttcn b/library/RLCMAC_Types.ttcn
index 97b89da..8688d36 100644
--- a/library/RLCMAC_Types.ttcn
+++ b/library/RLCMAC_Types.ttcn
@@ -576,8 +576,10 @@
 		payload := data
 	}
 
-	/* PTCCH/D (Packet Timing Advance Control Channel) message.
-	 * TODO: add a spec. reference to the message format definition. */
+/************************
+ * PTCCH/D (Packet Timing Advance Control Channel) message.
+ * TODO: add a spec. reference to the message format definition.
+ *************************/
 	type record PTCCHTimingAdvanceIE {
 		BIT1			spare ('0'B),
 		uint7_t			ta_val