dt-bindings: clock: fix rk3399 cru clock issues

The current rk3399 cru DT node gives warnings like:
'clocks' is a dependency of 'assigned-clocks'.

With the YAML conversion somehow "assigned-xxx" properties where added.
If a proper clock is added to the cru node these properties are no longer
needed, so removed them. Currently only one clock will be added, so limit
the clock maxItems to 1. Add a clock name to be able to differentiate
and filter bogus entries.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220329150742.22093-4-jbx6244@gmail.com


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