spi: dt-bindings: cleanup examples - indentation, lowercase hex

Cleanup examples:
 - use 4-space indentation (for cases when it is neither 4 not 2 space),
 - drop redundant blank lines,
 - use lowercase hex.

No functional impact except adjusting to preferred coding style.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> # renesas
Reviewed-by: Andrew Jeffery <andrew@aj.id.au> # aspeed
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> # meson
Link: https://lore.kernel.org/r/20230124083342.34869-2-krzysztof.kozlowski@linaro.org


Signed-off-by: Mark Brown <broonie@kernel.org>