Added register values and op-codes. Cleanup.

sx126x.h

@@ -55,7 +55,7 @@ public:
   void onReceive(void(*callback)(int));
 
   void receive(int size = 0);
-  void idle();
+  void standby();
   void sleep();
 
   bool preInit();
@@ -113,6 +113,8 @@ private:
   void optimizeModemSensitivity();
 
   void reset(void);
+  void calibrate(void);
+  void calibrate_image(long frequency);
 
 private:
   SPISettings _spiSettings;