dts: bindings: rtc: Add Xilinx RTC device tree binding

Add device tree binding for Xilinx RTC controller.

The RTC ensures accurate timekeeping using either auxiliary (VCCAUX_PMC)
or battery (VCC_BATT) power. It includes calibration logic to adjust for
temperature and voltage variations, supporting long-term accuracy. The RTC
generates periodic second tick and alarm interrupts for use by system
processors.

It features a 32-bit seconds counter (supports up to 136 years), a 16-bit
tick counter and a 4-bit fractional counter for fine-grained calibration.

Signed-off-by: Balanakakamal V <[email protected]>
Signed-off-by: Harini T <[email protected]>

Author: balanakv

dts/bindings/rtc/xlnx,rtc.yaml

@@ -0,0 +1,12 @@
+# Copyright (c) 2025 Advanced Micro Devices, Inc. (AMD)
+# SPDX-License-Identifier: Apache-2.0
+
+description: Xilinx RTC controller
+
+compatible: "xlnx,zynqmp-rtc"
+
+include: ["rtc.yaml", "rtc-device.yaml"]
+
+properties:
+  reg:
+    required: true