dt-bindings: slimbus: convert bus description to DT schema

Convert the SLIMbus bus description bindings to DT Schema.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221118065246.6835-11-srinivas.kandagatla@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>