dt-bindings: net: phy: Add support for NXP TJA11xx

Document the NXP TJA11xx PHY bindings.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/nxp,tja11xx.yaml

+# SPDX-License-Identifier: GPL-2.0+
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/nxp,tja11xx.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP TJA11xx PHY
+
+maintainers:
+  - Andrew Lunn <andrew@lunn.ch>
+  - Florian Fainelli <f.fainelli@gmail.com>
+  - Heiner Kallweit <hkallweit1@gmail.com>
+
+description:
+  Bindings for NXP TJA11xx automotive PHYs
+
+allOf:
+  - $ref: ethernet-phy.yaml#
+
+patternProperties:
+  "^ethernet-phy@[0-9a-f]+$":
+    type: object
+    description: |
+      Some packages have multiple PHYs. Secondary PHY should be defines as
+      subnode of the first (parent) PHY.
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 31
+        description:
+          The ID number for the child PHY. Should be +1 of parent PHY.
+
+    required:
+      - reg
+
+examples:
+  - |
+    mdio {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        tja1101_phy0: ethernet-phy@4 {
+            reg = <0x4>;
+        };
+    };
+  - |
+    mdio {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        tja1102_phy0: ethernet-phy@4 {
+            reg = <0x4>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            tja1102_phy1: ethernet-phy@5 {
+                reg = <0x5>;
+            };
+        };
+    };