pcu/GPRS_Components: send DATA.cnf in f_pcuif_rx_imm_ass()

The IUT expects a confirmation when Immediate Assignment is sent on PCH.

Change-Id: I585a1933dfb2119f1d3223b24db191282fd698b7
diff --git a/pcu/GPRS_Components.ttcn b/pcu/GPRS_Components.ttcn
index a85cd5e..7eff399 100644
--- a/pcu/GPRS_Components.ttcn
+++ b/pcu/GPRS_Components.ttcn
@@ -196,6 +196,12 @@
 		}
 
 		log("Rx Immediate Assignment: ", rr_imm_ass);
+
+		/* Send DATA.cnf back to the IUT (only needed for PCH) */
+		if (pcu_msg.u.data_req.sapi == PCU_IF_SAPI_PCH) {
+			f_pcuif_tx_data_cnf(pcu_msg);
+		}
+
 		setverdict(pass);
 		return true;
 		}