dt-bindings: aspeed-sgpio: Convert txt bindings to yaml.

sgpio-aspeed bindings should be converted to yaml format.

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210712100317.23298-2-steven_lee@aspeedtech.com
Signed-off-by: Joel Stanley <joel@jms.id.au>

Documentation/devicetree/bindings/gpio/aspeed,sgpio.yaml

@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/aspeed,sgpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Aspeed SGPIO controller
+
+maintainers:
+  - Andrew Jeffery <andrew@aj.id.au>
+
+description:
+  This SGPIO controller is for ASPEED AST2500 SoC, it supports up to 80 full
+  featured Serial GPIOs. Each of the Serial GPIO pins can be programmed to
+  support the following options
+  - Support interrupt option for each input port and various interrupt
+    sensitivity option (level-high, level-low, edge-high, edge-low)
+  - Support reset tolerance option for each output port
+  - Directly connected to APB bus and its shift clock is from APB bus clock
+    divided by a programmable value.
+  - Co-work with external signal-chained TTL components (74LV165/74LV595)
+
+properties:
+  compatible:
+    enum:
+      - aspeed,ast2400-sgpio
+      - aspeed,ast2500-sgpio
+
+  reg:
+    maxItems: 1
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+  interrupts:
+    maxItems: 1
+
+  interrupt-controller: true
+
+  clocks:
+    maxItems: 1
+
+  ngpios: true
+
+  bus-frequency: true
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - '#gpio-cells'
+  - interrupts
+  - interrupt-controller
+  - ngpios
+  - clocks
+  - bus-frequency
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/aspeed-clock.h>
+    sgpio: sgpio@1e780200 {
+        #gpio-cells = <2>;
+        compatible = "aspeed,ast2500-sgpio";
+        gpio-controller;
+        interrupts = <40>;
+        reg = <0x1e780200 0x0100>;
+        clocks = <&syscon ASPEED_CLK_APB>;
+        interrupt-controller;
+        ngpios = <80>;
+        bus-frequency = <12000000>;
+    };