dt-bindings: clock: drop minItems equal to maxItems

dt-bindings: clock: drop minItems equal to maxItems

minItems, if missing, are implicitly equal to maxItems, so drop
redundant piece to reduce size of code.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220825113334.196908-3-krzysztof.kozlowski@linaro.org
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>