Initial commit with basic project structure and Firebeetle 2 board definition

boards/espressif/esp8684_devkitm/esp8684_devkitm-pinctrl.dtsi

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2024 Espressif Systems (Shanghai) Co., Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/pinctrl/esp-pinctrl-common.h>
+#include <dt-bindings/pinctrl/esp32c2-pinctrl.h>
+#include <zephyr/dt-bindings/pinctrl/esp32c2-gpio-sigmap.h>
+
+&pinctrl {
+
+	uart0_default: uart0_default {
+		group1 {
+			pinmux = <UART0_TX_GPIO20>;
+			output-high;
+		};
+		group2 {
+			pinmux = <UART0_RX_GPIO19>;
+			bias-pull-up;
+		};
+	};
+};