Merge pull request zephyrproject-rtos#19 from AmbiqMicro/ap4-kxr-add-rtc

dts: arm: ambiq: ap4 kxr rtc driver

Author: RichardSWheatley

boards/ambiq/apollo4p_blue_kxr_evb/apollo4p_blue_kxr_evb.dts

@@ -25,6 +25,7 @@
 		led2 = &led2;
 		sw0 = &button0;
 		sw1 = &button1;
+		rtc = &rtc0;
 	};
 
 	leds {
@@ -67,6 +68,11 @@
 	status = "okay";
 };
 
+&rtc0 {
+	status = "okay";
+	clock = "XTAL";
+};
+
 &wdt0 {
 	status = "okay";
 };

dts/arm/ambiq/ambiq_apollo4p_blue.dtsi

@@ -313,6 +313,14 @@
 			ambiq,pwrcfg = <&pwrcfg 0x4 0x10000>;
 		};
 
+		rtc0: rtc@40004800 {
+			compatible = "ambiq,rtc";
+			reg = <0x40004800 0x210>;
+			interrupts = <2 0>;
+			alarms-count = <1>;
+			status = "disabled";
+		};
+
 		pinctrl: pin-controller@40010000 {
 			compatible = "ambiq,apollo4-pinctrl";
 			reg = <0x40010000 0x800>;