[E81][DTS] Add RV-3028 RTC under i2c1 with backup switch enabled

Backup-switch-mode set to "direct" to automatically switch to battery when power
goes down

arch/arm64/boot/dts/seco/include/e81-common.dtsi

@@ -814,6 +814,16 @@ &vreg_l9b_1p2 {
 };
 */
 
+// children of i2c1 (I2C_GP)
+&i2c1 {
+	rtc: rtc@52 {
+		compatible = "microcrystal,rv3028";
+		reg = <0x52>;
+		status = "okay";
+		backup-switch-mode = "direct";
+	};
+};
+
 // children of i2c2 (I2C_PM)
 &i2c2 {
 	// will be gpiochip3