samples: boards: esp32c6_devkitc: Add QDEC sample for PCNT

Add QDEC sample for PCNT driver testing.

Signed-off-by: Raffael Rostagno <raffael.rostagno@espressif.com>

Author: Raffael Rostagno

samples/sensor/qdec/boards/esp32c6_devkitc_hpcore.overlay

@@ -0,0 +1,42 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2025 Espressif Systems (Shanghai) Co., Ltd.
+ */
+
+/ {
+	aliases {
+		qdec0 = &pcnt;
+	};
+};
+
+&pinctrl {
+	pcnt_default: pcnt_default {
+		group1 {
+			pinmux = <PCNT0_CH0SIG_GPIO2>,
+				<PCNT0_CH0CTRL_GPIO3>;
+			bias-pull-up;
+		};
+	};
+};
+
+&pcnt {
+	pinctrl-0 = <&pcnt_default>;
+	pinctrl-names = "default";
+	status = "okay";
+	#address-cells = <1>;
+	#size-cells = <0>;
+	unit0@0 {
+		reg = <0>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		filter = <100>;
+		channelA@0 {
+			reg = <0>;
+			sig-pos-mode = <2>;
+			sig-neg-mode = <1>;
+			ctrl-h-mode = <0>;
+			ctrl-l-mode = <1>;
+		};
+	};
+};