dt-bindings: ptp: Add device tree binding for IDT 82P33 based PTP clock

Add device tree binding doc for the PTP clock based on IDT 82P33
Synchronization Management Unit (SMU).

Changes since v1:
 - As suggested by Rob Herring:
   1. Drop reg description for i2c
   2. Replace i2c@1 with i2c
   3. Add addtionalProperties: false
Signed-off-by: Min Li <min.li.xe@renesas.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/ptp/ptp-idt82p33.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ptp/ptp-idt82p33.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: IDT 82P33 PTP Clock Device Tree Bindings
+
+description: |
+  IDT 82P33XXX Synchronization Management Unit (SMU) based PTP clock
+
+maintainers:
+  - Min Li <min.li.xe@renesas.com>
+
+properties:
+  compatible:
+    enum:
+      - idt,82p33810
+      - idt,82p33813
+      - idt,82p33814
+      - idt,82p33831
+      - idt,82p33910
+      - idt,82p33913
+      - idt,82p33914
+      - idt,82p33931
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        phc@51 {
+            compatible = "idt,82p33810";
+            reg = <0x51>;
+        };
+    };