dt-bindings: soc: qcom,wcnss: convert to dtschema

Convert the Qualcomm WCNSS bindings to DT Schema.

Changes against original bindings: fix qcom,smd-channels and
qcom,smem-states names (how they are used in DTS and driver), enforce
child node naming of bluetooth and wifi.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220405065752.27389-3-krzysztof.kozlowski@linaro.org