dt-bindings: gpio: fairchild,74hc595: Convert to json-schema

Convert the Generic 8-bit shift register Device Tree binding
documentation to json-schema.

Rename from gpio-74x164 to fairchild,74hc595, as the former refers to
the Linux driver, and not to a hardware name.
Add the missing hog description.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Documentation/devicetree/bindings/gpio/fairchild,74hc595.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/fairchild,74hc595.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic 8-bit shift register
+
+maintainers:
+  - Maxime Ripard <mripard@kernel.org>
+
+properties:
+  compatible:
+    enum:
+      - fairchild,74hc595
+      - nxp,74lvc594
+
+  reg:
+    maxItems: 1
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    description:
+      The second cell is only used to specify the GPIO polarity.
+    const: 2
+
+  registers-number:
+    description: Number of daisy-chained shift registers
+
+  enable-gpios:
+    description: GPIO connected to the OE (Output Enable) pin.
+    maxItems: 1
+
+  spi-max-frequency: true
+
+patternProperties:
+  "^(hog-[0-9]+|.+-hog(-[0-9]+)?)$":
+    type: object
+
+    properties:
+      gpio-hog: true
+      gpios: true
+      output-high: true
+      output-low: true
+      line-name: true
+
+    required:
+      - gpio-hog
+      - gpios
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - '#gpio-cells'
+  - registers-number
+
+additionalProperties: false
+
+examples:
+  - |
+    spi {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            gpio5: gpio5@0 {
+                    compatible = "fairchild,74hc595";
+                    reg = <0>;
+                    gpio-controller;
+                    #gpio-cells = <2>;
+                    registers-number = <4>;
+                    spi-max-frequency = <100000>;
+            };
+    };

Documentation/devicetree/bindings/gpio/gpio-74x164.txt

-* Generic 8-bits shift register GPIO driver
-
-Required properties:
-- compatible: Should contain one of the following:
-    "fairchild,74hc595"
-    "nxp,74lvc594"
-- reg : chip select number
-- gpio-controller : Marks the device node as a gpio controller.
-- #gpio-cells : Should be two.  The first cell is the pin number and
-  the second cell is used to specify the gpio polarity:
-      0 = active high
-      1 = active low
-- registers-number: Number of daisy-chained shift registers
-
-Optional properties:
-- enable-gpios: GPIO connected to the OE (Output Enable) pin.
-
-Example:
-
-gpio5: gpio5@0 {
-	compatible = "fairchild,74hc595";
-	reg = <0>;
-	gpio-controller;
-	#gpio-cells = <2>;
-	registers-number = <4>;
-	spi-max-frequency = <100000>;
-};