dt-bindings: display: samsung,exynos5-dp: convert to DT Schema

Convert Samsung Exynos5250/5420 SoC Display Port Controller bindings to
DT schema with a change: add power-domains, already used in DTS.

This Display Port controller is actually variant of Analogix Display
Port bridge, however new DT Schema does not reference analogix,dp.yaml,
because of incompatibilities in the driver.  The analogix,dp.yaml
expects two ports, input and output, but Linux Exynos DP DRM driver and
DTS use only one port: output.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240313182855.14140-1-krzysztof.kozlowski@linaro.org


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