PM framework considers interconnect clocks as system clocks since they impact the functionality of the entire system including PMU. So, the control for changing these clocks at runtime is blocked by PMUFW. Interconnect clock frequency is configurable at design time in PCW. In ZU+, the interconnect clocks in both LPD and FPD can be configured depending on the bandwidth requirements for the application.
Here is a screen shot of Interconnect clock settings in PCW: