* T096, and Station G3: refactoring the 'FEM' prefs to variant-specific code

* CommonCLI: 'FEM' commands removed
* introduced static no-op attachDynamicPrefs() for all boards

src/helpers/NRF52Board.h

@@ -2,6 +2,7 @@
 
 #include <Arduino.h>
 #include <MeshCore.h>
+#include <helpers/KeyValueStore.h>
 
 #if defined(NRF52_PLATFORM)
 
@@ -57,6 +58,8 @@ public:
   virtual void sleep(uint32_t secs) override;
   bool isExternalPowered() override;
 
+  void attachDynamicPrefs(KeyValueStore* prefs) { }  // no-op
+
 #ifdef NRF52_POWER_MANAGEMENT
   uint16_t getBootVoltage() override { return boot_voltage_mv; }
   virtual uint32_t getResetReason() const override { return reset_reason; }