Move variant specific code

variants/xiao_c6/XiaoC6Board.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <Arduino.h>
+#include <helpers/ESP32Board.h>
+
+class XiaoC6Board : public ESP32Board {
+public:
+  void begin() {
+    ESP32Board::begin();
+
+#ifdef USE_XIAO_ESP32C6_EXTERNAL_ANTENNA
+// Connect an external antenna to your XIAO ESP32C6 otherwise, it may be damaged!
+    pinMode(3, OUTPUT);
+    digitalWrite(3, LOW); // Activate RF switch control
+
+    delay(100);
+
+    pinMode(14, OUTPUT);
+    digitalWrite(14, HIGH); // Use external antenna
+#endif
+  }
+
+  const char* getManufacturerName() const override {
+    return "Xiao C6";
+  }
+};
+
+