dt-bindings: phy: Add USB PHY support for Intel LGM SoC

Add the dt-schema to support USB PHY on Intel LGM SoC
Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200828022312.52724-2-vadivel.muruganx.ramuthevar@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/intel,lgm-usb-phy.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/intel,lgm-usb-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Intel LGM USB PHY Device Tree Bindings
+
+maintainers:
+  - Vadivel Murugan Ramuthevar <vadivel.muruganx.ramuthevar@linux.intel.com>
+
+properties:
+  compatible:
+    const: intel,lgm-usb-phy
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    items:
+      - description: USB PHY and Host controller reset
+      - description: APB BUS reset
+      - description: General Hardware reset
+
+  reset-names:
+    items:
+      - const: phy
+      - const: apb
+      - const: phy31
+
+  "#phy-cells":
+    const: 0
+
+required:
+  - compatible
+  - clocks
+  - reg
+  - resets
+  - reset-names
+  - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    usb-phy@e7e00000 {
+        compatible = "intel,lgm-usb-phy";
+        reg = <0xe7e00000 0x10000>;
+        clocks = <&cgu0 153>;
+        resets = <&rcu 0x70 0x24>,
+                 <&rcu 0x70 0x26>,
+                 <&rcu 0x70 0x28>;
+        reset-names = "phy", "apb", "phy31";
+        #phy-cells = <0>;
+    };