boards: esp32c6_devkitc: add i2c0 port

- Add I2C support in esp32c6_devkitc
- Update board documentation

Signed-off-by: Romain Pelletant <romain.pelletant@fullfreqs.com>

boards/espressif/esp32c6_devkitc/doc/index.rst

@@ -99,6 +99,8 @@ Current Zephyr's ESP32-C6-DevKitC board supports the following features:
 +------------+------------+-------------------------------------+
 | SPI Master | on-chip    | spi                                 |
 +------------+------------+-------------------------------------+
+| I2C        | on-chip    | i2c                                 |
++------------+------------+-------------------------------------+
 | Watchdog   | on-chip    | watchdog                            |
 +------------+------------+-------------------------------------+
 | LEDC       | on-chip    | pwm                                 |

boards/espressif/esp32c6_devkitc/esp32c6_devkitc-pinctrl.dtsi

@@ -32,4 +32,14 @@
 			output-low;
 		};
 	};
+
+	i2c0_default: i2c0_default {
+		group1 {
+			pinmux = <I2C0_SDA_GPIO6>,
+				 <I2C0_SCL_GPIO7>;
+			bias-pull-up;
+			drive-open-drain;
+			output-high;
+		};
+	};
 };

boards/espressif/esp32c6_devkitc/esp32c6_devkitc.dts

@@ -49,6 +49,13 @@
 	status = "okay";
 };
 
+&i2c0 {
+	status = "okay";
+	clock-frequency = <I2C_BITRATE_FAST>;
+	pinctrl-0 = <&i2c0_default>;
+	pinctrl-names = "default";
+};
+
 &spi2 {
 	#address-cells = <1>;
 	#size-cells = <0>;

boards/espressif/esp32c6_devkitc/esp32c6_devkitc.yaml

@@ -12,6 +12,7 @@ supported:
   - dma
   - spi
   - entropy
+  - i2c
 testing:
   ignore_tags:
     - bluetooth