arm64: dts: rockchip: minor whitespace cleanup around '='

The DTS code coding style expects exactly one space before and after '='
sign.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20231124095031.58555-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>