initial port of M5Stack Unit C6L, update pioarduino to newer bugfix release

variants/m5stack_unit_c6l/UnitC6LBoard.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <Arduino.h>
+#include <helpers/ESP32Board.h>
+
+class UnitC6LBoard : public ESP32Board {
+public:
+  void begin() {
+    ESP32Board::begin();
+  }
+
+  const char* getManufacturerName() const override {
+    return "Unit C6L";
+  }
+};