dt-bindings: soc: samsung: exynos-pmu: allow phys as child

The MIPI and DisplayPort phys are actually part of the Power Management
Unit system controller, thus allow them as its children, instead of
specifying as separate device nodes with syscon phandle.

Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230127194057.186458-2-krzysztof.kozlowski@linaro.org


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>