ARM: dts: aspeed: adjust whitespace around '='

Fix whitespace coding style: use single space instead of tabs or
multiple spaces around '=' sign in property assignment.  No functional
changes (same DTB).

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220526204127.831853-1-krzysztof.kozlowski@linaro.org