dt-bindings: timer: 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: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20250107131024.246561-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>