ARM: dts: exynos: fix MCT compatible in Universal C210

ARM: dts: exynos: fix MCT compatible in Universal C210

When desired, nodes should be disabled instead of changing their
compatible to a fake one:

  exynos4210-universal_c210.dtb: /soc/timer@10050000: failed to match any schema with compatible: ['none']

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20230221161653.56574-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>