dt-bindings: max77705: Add interrupt-controller property

Add interrupt-controller property, because max77705 has dedicated interrupt
source register to determine which sub device triggered an interrupt.

Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>

Documentation/devicetree/bindings/mfd/maxim,max77705.yaml

@@ -26,6 +26,18 @@ properties:
   interrupts:
     maxItems: 1
 
+  interrupt-controller:
+    description:
+      The driver implements an interrupt controller for the sub devices.
+      The interrupt number mapping is as follows
+      0 - charger
+      1 - topsys
+      2 - fuelgauge
+      3 - usb type-c management block.
+
+  '#interrupt-cells':
+    const: 1
+
   haptic:
     type: object
     additionalProperties: false
@@ -118,8 +130,10 @@ examples:
         pmic@66 {
             compatible = "maxim,max77705";
             reg = <0x66>;
+            #interrupt-cells = <1>;
             interrupt-parent = <&pm8998_gpios>;
             interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
+            interrupt-controller;
             pinctrl-0 = <&chg_int_default>;
             pinctrl-names = "default";