library/PCUIF_Types: make PCUIF version configurable

When changing the PCUIF, we have to maintain backwards compatibility
with the release versions of both osmo-pcu and osmo-bts, not only
with the recent master.  In order to achieve that, let's introduce
'mp_pcuif_version', so the PCUIF version can be adjusted.

Change-Id: I3cf7f908e606b91dd2cbddc168827dd074aed052
Related: SYS#4868, OS#4547
diff --git a/pcu/PCU_Tests.ttcn b/pcu/PCU_Tests.ttcn
index 09d91a0..20e3582 100644
--- a/pcu/PCU_Tests.ttcn
+++ b/pcu/PCU_Tests.ttcn
@@ -60,7 +60,7 @@
 
 /* FIXME: make sure to use parameters from mp_gb_cfg.cell_id in the PCU INFO IND */
 friend template (value) PCUIF_info_ind ts_PCUIF_INFO_default := {
-	version := PCU_IF_VERSION,
+	version := PCUIF_Types.mp_pcuif_version,
 	flags := c_PCUIF_Flags_default,
 	trx := valueof(ts_PCUIF_InfoTrxs_def),
 	bsic := 7,