dt-bindings: phy: bcm-ns-usb2-phy: convert to yaml

1. Convert from txt to yaml
2. Drop "Driver for" from the title
3. Document "#phy-cells"
4. Fix example node name (noticed by dt_binding_check)
5. Add #include to example (noticed by dt_binding_check)
6. Specify license
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210329165041.31574-1-zajec5@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/bcm-ns-usb2-phy.txt

-Driver for Broadcom Northstar USB 2.0 PHY
-
-Required properties:
-- compatible: brcm,ns-usb2-phy
-- reg: iomem address range of DMU (Device Management Unit)
-- reg-names: "dmu", the only needed & supported reg right now
-- clocks: USB PHY reference clock
-- clock-names: "phy-ref-clk", the only needed & supported clock right now
-
-To initialize USB 2.0 PHY driver needs to setup PLL correctly. To do this it
-requires passing phandle to the USB PHY reference clock.
-
-Example:
-	usb2-phy {
-		compatible = "brcm,ns-usb2-phy";
-		reg = <0x1800c000 0x1000>;
-		reg-names = "dmu";
-		#phy-cells = <0>;
-		clocks = <&genpll BCM_NSP_GENPLL_USB_PHY_REF_CLK>;
-		clock-names = "phy-ref-clk";
-	};

Documentation/devicetree/bindings/phy/bcm-ns-usb2-phy.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/bcm-ns-usb2-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom Northstar USB 2.0 PHY
+
+description: >
+  To initialize USB 2.0 PHY driver needs to setup PLL correctly.
+  To do this it requires passing phandle to the USB PHY reference clock.
+
+maintainers:
+  - Rafał Miłecki <rafal@milecki.pl>
+
+properties:
+  compatible:
+    const: brcm,ns-usb2-phy
+
+  reg:
+    items:
+      - description: iomem address range of DMU (Device Management Unit)
+
+  reg-names:
+    items:
+      - const: dmu
+
+  clocks:
+    items:
+      - description: USB PHY reference clock
+
+  clock-names:
+    items:
+      - const: phy-ref-clk
+
+  "#phy-cells":
+    const: 0
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - clocks
+  - clock-names
+  - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/bcm-nsp.h>
+    phy@1800c000 {
+        compatible = "brcm,ns-usb2-phy";
+        reg = <0x1800c000 0x1000>;
+        reg-names = "dmu";
+        clocks = <&genpll BCM_NSP_GENPLL_USB_PHY_REF_CLK>;
+        clock-names = "phy-ref-clk";
+        #phy-cells = <0>;
+    };