Transceiver52M: Set const qualifier on appropriate radio vector methods

Pointer accessor and noise average methods for radio and noise vectors
respectively.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
diff --git a/Transceiver52M/radioVector.h b/Transceiver52M/radioVector.h
index 0e83503..0566123 100644
--- a/Transceiver52M/radioVector.h
+++ b/Transceiver52M/radioVector.h
@@ -38,7 +38,7 @@
 	void setTime(const GSM::Time& wTime);
 	bool operator>(const radioVector& other) const;
 
-	signalVector *getVector(size_t chan = 0);
+	signalVector *getVector(size_t chan = 0) const;
 	bool setVector(signalVector *vector, size_t chan = 0);
 	size_t chans() const { return vectors.size(); }
 private:
@@ -50,7 +50,7 @@
 public:
 	noiseVector(size_t size = 0);
 	bool insert(float val);
-	float avg();
+	float avg() const;
 
 private:
 	size_t itr;