trx/radio_if.py: print type of RadioInterface

Change-Id: I6c1ba8546caec122cd1ea0ed87656f691abec068
diff --git a/python/trx/radio_if_uhd.py b/python/trx/radio_if_uhd.py
index b431fb6..ef2e0ed 100644
--- a/python/trx/radio_if_uhd.py
+++ b/python/trx/radio_if_uhd.py
@@ -27,6 +27,10 @@
 from radio_if import RadioInterface
 
 class RadioInterfaceUHD(RadioInterface):
+	# Human-readable description
+	def __str__(self):
+		return "UHD"
+
 	@property
 	def phy_proc_delay(self):
 		# FIXME: shall be measured (automatically?) for