regulator: dt-bindings: Add Awinic AW37503

Add aw37503 regulator device-tree binding documentation.
Signed-off-by: Alec Li <like@awinic.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230821035355.1269976-3-like@awinic.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/awinic,aw37503.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/awinic,aw37503.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Awinic AW37503 Voltage Regulator
+
+maintainers:
+  - Alec Li <like@awinic.com>
+
+description:
+  The AW37503 are dual voltage regulator, designed to support positive/negative
+  supply for driving TFT-LCD panels. It support software-configurable output
+  switching and monitoring. The output voltages can be programmed via an I2C
+  compatible interface.
+
+properties:
+  compatible:
+    const: awinic,aw37503
+
+  reg:
+    maxItems: 1
+
+patternProperties:
+  "^out[pn]$":
+    type: object
+    $ref: regulator.yaml#
+    unevaluatedProperties: false
+    description:
+      Properties for single regulator.
+
+    properties:
+      enable-gpios:
+        maxItems: 1
+        description:
+          GPIO specifier to enable the GPIO control (on/off) for regulator.
+
+    required:
+      - regulator-name
+
+required:
+  - compatible
+  - reg
+  - outp
+  - outn
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        regulator@3e {
+            compatible = "awinic,aw37503";
+            reg = <0x3e>;
+
+            outp {
+                regulator-name = "outp";
+                regulator-boot-on;
+                regulator-always-on;
+                enable-gpios = <&gpio 17 GPIO_ACTIVE_LOW>;
+            };
+
+            outn {
+                regulator-name = "outn";
+                regulator-boot-on;
+                regulator-always-on;
+                enable-gpios = <&gpio 27 GPIO_ACTIVE_LOW>;
+            };
+        };
+    };
+...
+