dt-bindings: clock: samsung,s2mps11: convert to dtschema

Convert the clock provider of Samsung S2MPS11 family of PMICs to DT
schema format.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Message-Id: <20211008113723.134648-4-krzysztof.kozlowski@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>