dt-bindings: power: supply: sbs-battery: Fix dtbs_check

Existing in-tree users make use of '"ti,bq20z45", "sbs,sbs-battery"', so
add it to the list of known compatible strings.

Also add missing support for the generic 'power-supplies' property by
importing power-supply.yaml and setting unevaluatedProperties instead
of additionalProperties.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/power/supply/sbs,sbs-battery.yaml

@@ -12,12 +12,15 @@ maintainers:
 description: |
   Battery compatible with the smart battery system specifications
 
-properties:
+allOf:
+  - $ref: power-supply.yaml#
 
+properties:
   compatible:
     oneOf:
       - items:
           - enum:
+              - ti,bq20z45
               - ti,bq20z65
               - ti,bq20z75
           - enum:
@@ -60,7 +63,7 @@ required:
   - compatible
   - reg
 
-additionalProperties: false
+unevaluatedProperties: false
 
 examples:
   - |