bts: Add PCU Interface testcases

Change-Id: I671b8e2c61705485f46602f648eb5fdc01db12f7
diff --git a/bts/BTS_Tests.default b/bts/BTS_Tests.default
index 562088b..fa8d0b0 100644
--- a/bts/BTS_Tests.default
+++ b/bts/BTS_Tests.default
@@ -13,6 +13,7 @@
 *.BTSVTY.CTRL_READMODE := "buffered"
 *.BTSVTY.CTRL_CLIENT_CLEANUP_LINEFEED := "yes"
 *.BTSVTY.PROMPT1 := "OsmoBTS> "
+*.PCU.socket_type := "SEQPACKET"
 
 [MODULE_PARAMETERS]
 Osmocom_VTY_Functions.mp_prompt_prefix := "OsmoBTS";