Transceiver52M: Use independent noise vectors for each channel

Each ARFCN channel may be independently configureted and possibly on
separate hardware, so don't share a single vector for noise estimate
calculations. Allow a non-pointer based iterator so we can get away
with using the default copy constructor.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
diff --git a/Transceiver52M/radioVector.h b/Transceiver52M/radioVector.h
index 9acce94..0e83503 100644
--- a/Transceiver52M/radioVector.h
+++ b/Transceiver52M/radioVector.h
@@ -48,12 +48,12 @@
 
 class noiseVector : std::vector<float> {
 public:
-	noiseVector(size_t len = 0);
+	noiseVector(size_t size = 0);
 	bool insert(float val);
 	float avg();
 
 private:
-	std::vector<float>::iterator it;
+	size_t itr;
 };
 
 class VectorFIFO : public InterthreadQueue<radioVector> { };