dt-bindings: mfd: samsung,exynos5433-lpass: Convert to dtschema

Convert the Exynos5433 LPASS bindings to DT schema format.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220202151310.285561-4-krzysztof.kozlowski@canonical.com