dt-bindings: soc: samsung: exynos-pmu: allow phys as child on Exynos3 and Exynos4

Just like on Exynos5250, Exynos5420 and Exynos5433 the MIPI phy is
actually part of the Power Management Unit system controller thus allow
it as PMU's child.

Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230207192851.549242-1-krzysztof.kozlowski@linaro.org


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