Move all GPRS helper function to its own file and component

This is a first step towards refactoring of all functions to use MS and
Ul/DlTBF objects containing state.

Change-Id: Ieae27d6e707f79ec2145864ef5cd67ddbbec9314
diff --git a/pcu/PCU_selftest.ttcn b/pcu/PCU_selftest.ttcn
index 15cdd80..70138bf 100644
--- a/pcu/PCU_selftest.ttcn
+++ b/pcu/PCU_selftest.ttcn
@@ -25,6 +25,7 @@
 import from RLCMAC_CSN1_Types all;
 import from RLCMAC_Types all;
 import from RLCMAC_Templates all;
+import from GPRS_Components all;
 import from PCU_Tests all;
 
 type component dummy_CT extends BSSGP_Client_CT {