Transceiver52M: Set variable thread priority levels

The transceiver and underlying device drivers are threaded. use
the following priority levels.

0.50 - UHD driver internal threads
0.45 - Receive device drive thread
0.44 - Transmit device drive thread
0.43 - UHD asynchronous update thread (error reporting)
0.42 - Receive burst processing thread(s)

Signed-off-by: Thomas Tsou <tom@tsou.cc>
diff --git a/Transceiver52M/Transceiver.h b/Transceiver52M/Transceiver.h
index 4356ef2..d1a6ec9 100644
--- a/Transceiver52M/Transceiver.h
+++ b/Transceiver52M/Transceiver.h
@@ -235,7 +235,7 @@
   void reset();
 
   /** set priority on current thread */
-  void setPriority() { mRadioInterface->setPriority(); }
+  void setPriority(float prio = 0.5) { mRadioInterface->setPriority(prio); }
 
 };