Implement 'agc' reset for SX126x & LR11x0 chip families (#9705)

* Implement 'agc' reset for SX126x chip family

There's no actual agc on SX126x chips but you can reset the analog
registers by doing a warm sleep & running calibration.

* Address PR comments & implement for LR11x0 too

* calibrate for configured frequency band

* Gate LR11X0_AGC_RESET

src/mesh/LR11x0Interface.h

@@ -27,6 +27,10 @@ template <class T> class LR11x0Interface : public RadioLibInterface
 
     bool isIRQPending() override { return lora.getIrqFlags() != 0; }
 
+#ifdef LR11X0_AGC_RESET
+    void resetAGC() override;
+#endif
+
   protected:
     /**
      * Specific module instance