dts: arm: Add rtc device node for Renesas RA family

Add rtc device node to support rtc
driver on Renesas RA SoCs:
- r7fa8d1bhecbd
- r7ka8p1kflcac
- r7fa8m1ahecbd
- r7fa4l1bd4cfp

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

Author: khoatranyj

dts/arm/renesas/ra/ra4/r7fa4l1bx.dtsi

@@ -576,6 +576,14 @@
 			status = "disabled";
 		};
 
+		rtc: rtc@40083000 {
+			compatible = "renesas,ra-rtc";
+			reg = <40083000 0x80>;
+			clocks = <&subclk>;
+			alarms-count = <1>;
+			status = "disabled";
+		};
+
 		option_setting_ofs0: option-setting-ofs0@100a100 {
 			compatible = "zephyr,memory-region";
 			zephyr,memory-region = "OFS_OFS0_MEMORY";

dts/arm/renesas/ra/ra8/ra8x1.dtsi

@@ -974,6 +974,14 @@
 			status = "disabled";
 		};
 
+		rtc: rtc@40202000 {
+			compatible = "renesas,ra-rtc";
+			reg = <0x40202000 0x80>;
+			clocks = <&subclk>;
+			alarms-count = <1>;
+			status = "disabled";
+		};
+
 		option_setting_ofs0: option-setting-ofs0@300a100 {
 			compatible = "zephyr,memory-region";
 			zephyr,memory-region = "OFS_OFS0_MEMORY";

dts/arm/renesas/ra/ra8/ra8x2.dtsi

@@ -1078,6 +1078,14 @@
 			status = "disabled";
 		};
 
+		rtc: rtc@40202000 {
+			compatible = "renesas,ra-rtc";
+			reg = <0x40202000 0x80>;
+			clocks = <&subclk>;
+			alarms-count = <1>;
+			status = "disabled";
+		};
+
 		option_setting_ofs_conf_sec: option-setting-ofs-conf-sec@2c9f040 {
 			reg = <0x02c9f040 0x3c0>;
 			#address-cells = <1>;