dt-bindings: memory: convert Samsung Exynos DMC to dtschema

Convert Samsung Exynos5422 SoC frequency and voltage scaling for
Dynamic Memory Controller to DT schema format using json-schema.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20210820150353.161161-3-krzysztof.kozlowski@canonical.com


Signed-off-by: Rob Herring <robh@kernel.org>