dt-bindings: clock: add rk3588 cru bindings

Document the device tree bindings of the rockchip rk3588 SoC
clock and reset unit.
Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20221018151407.63395-4-sebastian.reichel@collabora.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

Documentation/devicetree/bindings/clock/rockchip,rk3588-cru.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/rockchip,rk3588-cru.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Rockchip rk3588 Family Clock and Reset Control Module
+
+maintainers:
+  - Elaine Zhang <zhangqing@rock-chips.com>
+  - Heiko Stuebner <heiko@sntech.de>
+
+description: |
+  The RK3588 clock controller generates the clock and also implements a reset
+  controller for SoC peripherals. For example it provides SCLK_UART2 and
+  PCLK_UART2, as well as SRST_P_UART2 and SRST_S_UART2 for the second UART
+  module.
+  Each clock is assigned an identifier and client nodes can use this identifier
+  to specify the clock which they consume. All available clock and reset IDs
+  are defined as preprocessor macros in dt-binding headers.
+
+properties:
+  compatible:
+    enum:
+      - rockchip,rk3588-cru
+
+  reg:
+    maxItems: 1
+
+  "#clock-cells":
+    const: 1
+
+  "#reset-cells":
+    const: 1
+
+  clocks:
+    minItems: 2
+    maxItems: 2
+
+  clock-names:
+    items:
+      - const: xin24m
+      - const: xin32k
+
+  assigned-clocks: true
+
+  assigned-clock-rates: true
+
+  rockchip,grf:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: >
+      phandle to the syscon managing the "general register files". It is used
+      for GRF muxes, if missing any muxes present in the GRF will not be
+      available.
+
+required:
+  - compatible
+  - reg
+  - "#clock-cells"
+  - "#reset-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    cru: clock-controller@fd7c0000 {
+      compatible = "rockchip,rk3588-cru";
+      reg = <0xfd7c0000 0x5c000>;
+      #clock-cells = <1>;
+      #reset-cells = <1>;
+    };