regulator: rtq6752: Add binding document for Richtek RTQ6752

Add binding document for Richtek RTQ6752.
Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Link: https://lore.kernel.org/r/1625845236-30285-1-git-send-email-u0084500@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/richtek,rtq6752-regulator.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/richtek,rtq6752-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Richtek RTQ6752 TFT LCD Voltage Regulator
+
+maintainers:
+  - ChiYuan Huang <cy_huang@richtek.com>
+
+description: |
+  The RTQ6752 is an I2C interface pgorammable power management IC. It includes
+  two synchronous boost converter for PAVDD, and one synchronous NAVDD
+  buck-boost. The device is suitable for automotive TFT-LCD panel.
+
+properties:
+  compatible:
+    enum:
+      - richtek,rtq6752
+
+  reg:
+    maxItems: 1
+
+  enable-gpios:
+    description: |
+      A connection of the chip 'enable' gpio line. If not provided, treat it as
+      external pull up.
+    maxItems: 1
+
+  regulators:
+    type: object
+    $ref: regulator.yaml#
+
+    patternProperties:
+      "^(p|n)avdd$":
+        type: object
+        $ref: regulator.yaml#
+        description: |
+          regulator description for pavdd and navdd.
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - regulators
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      rtq6752@6b {
+        compatible = "richtek,rtq6752";
+        status = "okay";
+        reg = <0x6b>;
+        enable-gpios = <&gpio26 2 0>;
+
+        regulators {
+          pavdd {
+            regulator-name = "rtq6752-pavdd";
+            regulator-min-microvolt = <5000000>;
+            regulator-max-microvolt = <7300000>;
+            regulator-boot-on;
+          };
+          navdd {
+            regulator-name = "rtq6752-navdd";
+            regulator-min-microvolt = <5000000>;
+            regulator-max-microvolt = <7300000>;
+            regulator-boot-on;
+          };
+        };
+      };
+    };