pcu: Enable 'egprs only' vty option if egprs requested

Change-Id: Idd0b5bf8769d693480268c0a0b89dbfd63779e48
diff --git a/src/osmo_gsm_tester/pcu.py b/src/osmo_gsm_tester/pcu.py
index 9ec8f35..cc338cf 100644
--- a/src/osmo_gsm_tester/pcu.py
+++ b/src/osmo_gsm_tester/pcu.py
@@ -34,6 +34,13 @@
         self.bts = bts
         self.conf = conf
 
+########################
+# PUBLIC - INTERNAL API
+########################
+
+    def egprs_enabled(self):
+        return self.bts.egprs_enabled()
+
 ###################
 # PUBLIC (test API included)
 ###################