tests: adc: update overlay for adc test

Add interrupts information for these boards:
- ek_ra8m1
- ek_ra8d1
- mck_ra8t1

Signed-off-by: The Nguyen <the.nguyen.yf@renesas.com>

Author: thenguyenyf

tests/drivers/adc/adc_api/boards/ek_ra8d1.overlay

@@ -24,6 +24,8 @@
 &adc1 {
 	pinctrl-0 = <&adc1_default>;
 	pinctrl-names = "default";
+	interrupts = <95 12>;
+	interrupt-names = "scanend";
 	status = "okay";
 	#address-cells = <1>;
 	#size-cells = <0>;

tests/drivers/adc/adc_api/boards/ek_ra8m1.overlay

@@ -24,6 +24,8 @@
 &adc1 {
 	pinctrl-0 = <&adc1_default>;
 	pinctrl-names = "default";
+	interrupts = <95 12>;
+	interrupt-names = "scanend";
 	status = "okay";
 	#address-cells = <1>;
 	#size-cells = <0>;

tests/drivers/adc/adc_api/boards/mck_ra8t1.overlay

@@ -24,6 +24,8 @@
 &adc1 {
 	pinctrl-0 = <&adc1_default>;
 	pinctrl-names = "default";
+	interrupts = <95 12>;
+	interrupt-names = "scanend";
 	status = "okay";
 	#address-cells = <1>;
 	#size-cells = <0>;