dt-bindings: display/msm: *dpu.yaml: split required properties clauses

dt-bindings: display/msm: *dpu.yaml: split required properties clauses

Require only properties declared in given schema, which makes the code a
bit more readable and easy to follow.

Suggested-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/514229/
Link: https://lore.kernel.org/r/20221207012231.112059-2-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>