adding parameter in uesoftmodem for uhd trx thread

targets/RT/USER/lte-uesoftmodem.c

@@ -171,6 +171,8 @@ extern void get_uethreads_params(void);
 
 int transmission_mode=1;
 
+int usrp_tx_thread = 0;
+
 
 char *usrp_args=NULL;
 char *usrp_clksrc=NULL;