dt-bindings: phy: convert meson-gxl-usb2-phy.txt to dt-schema

Convert the Amlogic Meson GXL USB2 PHY bindings to dt-schema.

Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Martin Blumenstingl <[e-mail]>
Signed-off-by: Neil Armstrong <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

Documentation/devicetree/bindings/phy/amlogic,meson-gxl-usb2-phy.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/amlogic,meson-gxl-usb2-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Amlogic Meson GXL USB2 PHY
+
+maintainers:
+  - Neil Armstrong <[e-mail]>
+
+properties:
+  compatible:
+    const: amlogic,meson-gxl-usb2-phy
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: phy
+
+  resets:
+    maxItems: 1
+
+  reset-names:
+    items:
+      - const: phy
+
+  "#phy-cells":
+    const: 0
+
+  phy-supply: true
+
+required:
+  - compatible
+  - reg
+  - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    phy@78000 {
+        compatible = "amlogic,meson-gxl-usb2-phy";
+        reg = <0x78000 0x20>;
+        clocks = <&xtal>;
+        clock-names = "phy";
+        resets = <&phy_reset>;
+        reset-names = "phy";
+        #phy-cells = <0>;
+        phy-supply = <&usb2_supply>;
+    };

Documentation/devicetree/bindings/phy/meson-gxl-usb2-phy.txt

···
-* Amlogic Meson GXL and GXM USB2 PHY binding
-
-Required properties:
-- compatible:	Should be "amlogic,meson-gxl-usb2-phy"
-- reg:		The base address and length of the registers
-- #phys-cells:	must be 0 (see phy-bindings.txt in this directory)
-
-Optional properties:
-- clocks:	a phandle to the clock of this PHY
-- clock-names:	must be "phy"
-- resets:	a phandle to the reset line of this PHY
-- reset-names:	must be "phy"
-- phy-supply:	see phy-bindings.txt in this directory
-
-
-Example:
-	usb2_phy0: phy@78000 {
-		compatible = "amlogic,meson-gxl-usb2-phy";
-		#phy-cells = <0>;
-		reg = <0x0 0x78000 0x0 0x20>;
-	};