dt-bindings: mfd: Add document bindings for mp2629

Add device tree binding information for mp2629 mfd driver.
Signed-off-by: Saravanan Sekar <sravanhome@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Documentation/devicetree/bindings/mfd/mps,mp2629.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/mps,mp2629.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MP2629 Battery Charger PMIC from Monolithic Power System.
+
+maintainers:
+  - Saravanan Sekar <sravanhome@gmail.com>
+
+description: |
+  MP2629 is a PMIC providing battery charging and power supply for smartphones,
+  wireless camera and portable devices. Chip is controlled over I2C.
+
+  The battery charge management device handles battery charger controller and
+  ADC IIO device for battery, system voltage
+
+properties:
+  compatible:
+    const: mps,mp2629
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 2
+    description:
+      The first cell is the IRQ number, the second cell is the trigger type.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-controller
+  - "#interrupt-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/input/linux-event-codes.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        pmic@4b {
+            compatible = "mps,mp2629";
+            reg = <0x4b>;
+
+            interrupt-controller;
+            interrupt-parent = <&gpio2>;
+            #interrupt-cells = <2>;
+            interrupts = <3 IRQ_TYPE_LEVEL_HIGH>;
+        };
+    };