arm64: dts: qcom: sc8280xp-pmics: add pmk8280 rtc

The PMK8280 has an RTC which can also be used as a wakeup source.

Note that the RTC can not be disabled and updating the time is not
permitted either. Instead an offset can be stored in some other machine-
specific non-volatile memory which a driver can take into account.
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230202155448.6715-20-johan+linaro@kernel.org

arch/arm64/boot/dts/qcom/sc8280xp-pmics.dtsi

@@ -95,6 +95,15 @@ pmk8280_adc_tm: adc-tm@3400 {
 			#thermal-sensor-cells = <1>;
 			status = "disabled";
 		};
+
+		pmk8280_rtc: rtc@6100 {
+			compatible = "qcom,pmk8350-rtc";
+			reg = <0x6100>, <0x6200>;
+			reg-names = "rtc", "alarm";
+			interrupts = <0x0 0x62 0x1 IRQ_TYPE_EDGE_RISING>;
+			wakeup-source;
+			status = "disabled";
+		};
 	};
 
 	pmc8280_1: pmic@1 {