boards: esp32c6_devkitc: Add i2s support and samples

Add default configs for i2s and onboard LED and i2s output samples.

Signed-off-by: Raffael Rostagno <[email protected]>

Author: Raffael Rostagno

boards/espressif/esp32c6_devkitc/esp32c6_devkitc_hpcore.yaml

@@ -16,6 +16,7 @@ supported:
   - counter
   - entropy
   - i2c
+  - i2s
 testing:
   ignore_tags:
     - bluetooth

samples/drivers/i2s/output/boards/esp32c6_devkitc_hpcore.overlay

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2025 Espressif Systems (Shanghai) Co., Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	aliases {
+		i2s-tx = &i2s;
+	};
+};
+
+&pinctrl {
+	i2s_default: i2s_default {
+		group1 {
+			pinmux = <I2S_MCLK_GPIO6>,
+				 <I2S_O_WS_GPIO5>,
+				 <I2S_O_BCK_GPIO4>,
+				 <I2S_O_SD_GPIO3>;
+		};
+		group2 {
+			pinmux = <I2S_I_SD_GPIO2>;
+		};
+	};
+};
+
+&i2s {
+	status = "okay";
+	pinctrl-0 = <&i2s_default>;
+	pinctrl-names = "default";
+
+	dmas = <&dma 3>;
+	dma-names = "tx";
+};
+
+&dma {
+	status = "okay";
+};

samples/drivers/led/led_strip/boards/esp32c6_devkitc_hpcore.overlay

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2025 Espressif Systems (Shanghai) Co., Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/led/led.h>
+
+/ {
+	aliases {
+		led-strip = &led_strip;
+	};
+};
+
+&pinctrl {
+	i2s_default: i2s_default {
+		group1 {
+			pinmux = <I2S_MCLK_GPIO6>,
+				 <I2S_O_WS_GPIO5>,
+				 <I2S_O_BCK_GPIO4>,
+				 <I2S_O_SD_GPIO8>;
+		};
+		group2 {
+			pinmux = <I2S_I_SD_GPIO2>;
+		};
+	};
+};
+
+i2s_led: &i2s {
+	status = "okay";
+	pinctrl-0 = <&i2s_default>;
+	pinctrl-names = "default";
+
+	dmas = <&dma 3>;
+	dma-names = "tx";
+
+	led_strip: ws2812@0 {
+		compatible = "worldsemi,ws2812-i2s";
+
+		reg = <0>;
+		chain-length = <1>;
+		color-mapping = <LED_COLOR_ID_GREEN
+				 LED_COLOR_ID_RED
+				 LED_COLOR_ID_BLUE>;
+		reset-delay = <500>;
+	};
+};
+
+&dma {
+	status = "okay";
+};