dt-bindings: timer: samsung,exynos4210-mct: define strict clock order

The DTS should always have fixed clock order, even if it comes with
clock-names property.  Drop the pattern to make the order strict.
Existing DTS already match this.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220424150333.75172-3-krzysztof.kozlowski@linaro.org