dt-bindings: clock: rk3188-cru-common: remove CLK_NR_CLKS

CLK_NR_CLKS should not be part of the binding.
Remove since the kernel code no longer uses it.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/6f21c09b-e8d2-4749-aca6-572c79df775d@gmail.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>