dt-bindings: usb: Add Realtek DHC RTD SoC Type-C

Document the device-tree bindings for Realtek SoCs Type-C.
Realtek DHC (digital home center) RTD SoCs support a Type-C module.

Link: https://lore.kernel.org/lkml/[e-mail]/
Signed-off-by: Stanley Chang <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Chanwoo Choi <[e-mail]>

Documentation/devicetree/bindings/usb/realtek,rtd-type-c.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2023 Realtek Semiconductor Corporation
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/realtek,rtd-type-c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Realtek DHC RTD SoCs USB Type-C Connector detection
+
+maintainers:
+  - Stanley Chang <[e-mail]>
+
+description:
+  Realtek digital home center (DHC) RTD series SoCs include a type c module.
+  This module is able to detect the state of type c connector.
+
+properties:
+  compatible:
+    enum:
+      - realtek,rtd1295-type-c
+      - realtek,rtd1312c-type-c
+      - realtek,rtd1315e-type-c
+      - realtek,rtd1319-type-c
+      - realtek,rtd1319d-type-c
+      - realtek,rtd1395-type-c
+      - realtek,rtd1619-type-c
+      - realtek,rtd1619b-type-c
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  nvmem-cell-names:
+    items:
+      - const: usb-cal
+
+  nvmem-cells:
+    maxItems: 1
+    description:
+      The phandle to nvmem cell that contains the trimming data.
+      The type c parameter trimming data specified via efuse.
+      If unspecified, default value is used.
+
+  realtek,rd-ctrl-gpios:
+    description: The gpio node to control external Rd on board.
+    maxItems: 1
+
+  connector:
+    $ref: /schemas/connector/usb-connector.yaml#
+    description: Properties for usb c connector.
+    type: object
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    type-c@7220 {
+        compatible = "realtek,rtd1619b-type-c";
+        reg = <0x7220 0x20>;
+        interrupts = <0 60 IRQ_TYPE_LEVEL_HIGH>;
+
+        pinctrl-names = "default";
+        pinctrl-0 = <&usb_cc1_pins>, <&usb_cc2_pins>;
+        nvmem-cells = <&otp_usb_cal>;
+        nvmem-cell-names = "usb-cal";
+
+        connector {
+            compatible = "usb-c-connector";
+            label = "USB-C";
+            data-role = "dual";
+            power-role = "dual";
+        };
+    };