dt-bindings: arm: qcom: Document asus,sparrow device

Document the ASUS ZenWatch 2 ("sparrow") which is a smartwatch based on
Snapdragon 400 SoC.
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220226101939.1011551-1-luca@z3ntu.xyz

Documentation/devicetree/bindings/arm/qcom.yaml

@@ -99,6 +99,7 @@ properties:
 
       - items:
           - enum:
+              - asus,sparrow
               - lg,lenok
           - const: qcom,apq8026