dt-bindings: display: Correct indentation and style in DTS example

DTS example in the bindings should be indented with 2- or 4-spaces and
aligned with opening '- |', so correct any differences like 3-spaces or
mixtures 2- and 4-spaces in one binding.

No functional changes here, but saves some comments during reviews of
new patches built on existing code.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # msm
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> # renesas
Link: https://lore.kernel.org/r/20250107125854.227233-1-krzysztof.kozlowski@linaro.org


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