enb: add rx_ant param

Change-Id: Iada98fce3608808914562d9f7e2af2c230e03cae
diff --git a/src/osmo_gsm_tester/obj/enb.py b/src/osmo_gsm_tester/obj/enb.py
index 80f7b6e..252fa14 100644
--- a/src/osmo_gsm_tester/obj/enb.py
+++ b/src/osmo_gsm_tester/obj/enb.py
@@ -34,6 +34,7 @@
         'tdd_uldl_config': schema.UINT,
         'tdd_special_subframe_pattern': schema.UINT,
         'transmission_mode': schema.LTE_TRANSMISSION_MODE,
+        'rx_ant': schema.STR,
         'tx_gain': schema.UINT,
         'rx_gain': schema.UINT,
         'rf_dev_type': schema.STR,