dt-bindings: clock: cirrus,lochnagar: add top-level constraints

Properties with variable number of items per each device are expected to
have widest constraints in top-level "properties:" block and further
customized (narrowed) in "if:then:".  Add missing top-level constraints
for clocks.  Drop also redundant assigned-clocks properties, because
core dtschema allows them if clocks are provided.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240818173014.122073-2-krzysztof.kozlowski@linaro.org


Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>