trx/radio_if.py: fix: use proper block name

Since the 'TRX Burst Interface' block was renamed,
the followgraph is broken. Let's fix it.
diff --git a/python/trx/radio_if.py b/python/trx/radio_if.py
index 40fcabb..661025a 100644
--- a/python/trx/radio_if.py
+++ b/python/trx/radio_if.py
@@ -98,8 +98,8 @@
 		self.gsm_clck_ctrl = grgsm.clock_offset_control(
 			shift_fc, self.samp_rate, osr = 4)
 
-		self.gsm_trx_if = grgsm.trx(self.trx_remote_addr,
-			str(self.trx_base_port))
+		self.gsm_trx_burst_if = grgsm.trx_burst_if(
+			self.trx_remote_addr, str(self.trx_base_port))
 
 		##################################################
 		# Connections
@@ -115,7 +115,7 @@
 			(self.gsm_input, 'ctrl_in'))
 
 		self.msg_connect((self.gsm_receiver, 'C0'),
-			(self.gsm_trx_if, 'bursts'))
+			(self.gsm_trx_burst_if, 'bursts'))
 
 	def check_available(self):
 		return self.fc_set