tests: drivers: pwm: Add support test PWM for ek_ra4c1

Add support test app pwm_loopback for ek_ra4c1 board

Signed-off-by: Khoa Nguyen <[email protected]>

Author: khoa-nguyen-18

tests/drivers/pwm/pwm_loopback/boards/ek_ra4c1.overlay

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2025 Renesas Electronics Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/pwm/pwm.h>
+#include <zephyr/dt-bindings/pwm/ra_pwm.h>
+
+/ {
+	pwm_loopback_0 {
+		compatible = "test-pwm-loopback";
+		pwms = <&pwm0 0 0 PWM_POLARITY_NORMAL>,
+			<&pwm4 0 0 PWM_POLARITY_NORMAL>;
+	};
+};
+
+&pinctrl {
+	pwm0_default: pwm0_default {
+		group1 {
+			/* GTIOC0A*/
+			psels = <RA_PSEL(RA_PSEL_GPT1, 4, 15)>;
+		};
+	};
+};
+
+&pwm0 {
+	pinctrl-0 = <&pwm0_default>;
+	pinctrl-names = "default";
+	interrupts = <62 1>, <63 1>;
+	interrupt-names = "gtioca", "overflow";
+	status = "okay";
+};