dt-bindings: Add Qualcomm USB SuperSpeed PHY bindings

Binding description for Qualcomm's Synopsys 1.0.0 SuperSpeed PHY. This PHY
appears in a number of SoCs on various flavors of 20nm and 28nm nodes.

This commit adds information related to the 28nm node only.

Based on Sriharsha Allenki's <sallenki@codeaurora.org> original
definitions.

[bod: converted to yaml format]
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Cc: Jorge Ramirez-Ortiz <jorge.ramirez.ortiz@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Jorge Ramirez-Ortiz <jorge.ramirez.ortiz@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Documentation/devicetree/bindings/phy/qcom,usb-ss.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/phy/qcom,usb-ss.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Qualcomm Synopsys 1.0.0 SuperSpeed USB PHY
+
+maintainers:
+  - Bryan O'Donoghue <bryan.odonoghue@linaro.org>
+
+description: |
+  Qualcomm Synopsys 1.0.0 SuperSpeed USB PHY
+
+properties:
+  compatible:
+    enum:
+      - qcom,usb-ss-28nm-phy
+
+  reg:
+    maxItems: 1
+
+  "#phy-cells":
+    const: 0
+
+  clocks:
+    items:
+      - description: rpmcc clock
+      - description: PHY AHB clock
+      - description: SuperSpeed pipe clock
+
+  clock-names:
+    items:
+      - const: ref
+      - const: ahb
+      - const: pipe
+
+  vdd-supply:
+    description: phandle to the regulator VDD supply node.
+
+  vdda1p8-supply:
+    description: phandle to the regulator 1.8V supply node.
+
+  resets:
+    items:
+      - description: COM reset
+      - description: PHY reset line
+
+  reset-names:
+    items:
+      - const: com
+      - const: phy
+
+required:
+  - compatible
+  - reg
+  - "#phy-cells"
+  - clocks
+  - clock-names
+  - vdd-supply
+  - vdda1p8-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/qcom,gcc-qcs404.h>
+    #include <dt-bindings/clock/qcom,rpmcc.h>
+    usb3_phy: usb3-phy@78000 {
+        compatible = "qcom,usb-ss-28nm-phy";
+        reg = <0x78000 0x400>;
+        #phy-cells = <0>;
+        clocks = <&rpmcc RPM_SMD_LN_BB_CLK>,
+                 <&gcc GCC_USB_HS_PHY_CFG_AHB_CLK>,
+                 <&gcc GCC_USB3_PHY_PIPE_CLK>;
+        clock-names = "ref", "ahb", "pipe";
+        resets = <&gcc GCC_USB3_PHY_BCR>,
+                 <&gcc GCC_USB3PHY_PHY_BCR>;
+        reset-names = "com", "phy";
+        vdd-supply = <&vreg_l3_1p05>;
+        vdda1p8-supply = <&vreg_l5_1p8>;
+    };
+...