dt-bindings: phy: Convert ti,dm816x-usb-phy to DT schema

Convert the TI DM816x USB PHY binding to DT schema format. It's a
straight forward conversion.

Signed-off-by: Rob Herring (Arm) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

Documentation/devicetree/bindings/phy/dm816x-phy.txt

···
-Device tree binding documentation for am816x USB PHY
-=========================
-
-Required properties:
-- compatible : should be "ti,dm816x-usb-phy"
-- reg : offset and length of the PHY register set.
-- reg-names : name for the phy registers
-- clocks : phandle to the clock
-- clock-names : name of the clock
-- syscon: phandle for the syscon node to access misc registers
-- #phy-cells : from the generic PHY bindings, must be 1
-- syscon: phandle for the syscon node to access misc registers
-
-Example:
-
-usb_phy0: usb-phy@20 {
-	compatible = "ti,dm8168-usb-phy";
-	reg = <0x20 0x8>;
-	reg-names = "phy";
-	clocks = <&main_fapll 6>;
-	clock-names = "refclk";
-	#phy-cells = <0>;
-	syscon = <&scm_conf>;
-};

Documentation/devicetree/bindings/phy/ti,dm8168-usb-phy.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/ti,dm8168-usb-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI DM8168 USB PHY
+
+maintainers:
+  - Tony Lindgren <[e-mail]>
+
+properties:
+  compatible:
+    const: ti,dm8168-usb-phy
+
+  reg:
+    maxItems: 1
+
+  reg-names:
+    items:
+      - const: phy
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: refclk
+
+  '#phy-cells':
+    const: 0
+
+  syscon:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: Phandle for the syscon node to access misc registers.
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - clocks
+  - clock-names
+  - '#phy-cells'
+  - syscon
+
+additionalProperties: false
+
+examples:
+  - |
+    usb-phy@20 {
+        compatible = "ti,dm8168-usb-phy";
+        reg = <0x20 0x8>;
+        reg-names = "phy";
+        clocks = <&main_fapll 6>;
+        clock-names = "refclk";
+        #phy-cells = <0>;
+        syscon = <&scm_conf>;
+    };