dt-bindings: power: supply: charger-manager: Add missing type for 'cm-battery-stat'

'cm-battery-stat' is missing a type definition and is not a common
property. The type is boolean.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220719215017.1875530-1-robh@kernel.org

Documentation/devicetree/bindings/power/supply/charger-manager.yaml

@@ -50,6 +50,7 @@ properties:
 
   cm-battery-stat:
     description: battery status
+    $ref: /schemas/types.yaml#/definitions/uint32
     enum:
       - 0 # battery always present
       - 1 # no battery