arm64: dts: sprd: minor whitespace cleanup

The DTS code coding style expects exactly one space before '{'
character.

Link: https://lore.kernel.org/r/20240208105137.128601-1-krzysztof.kozlowski@linaro.org


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