The correct command to configure the controller to update Cisco CMX every 5 seconds for rogue devices is
"config nmsp notification interval rssi rogues 5". NMSP (Network Mobility Services Protocol) is used by Cisco wireless controllers to manage and communicate with connected services such as Cisco CMX. The command structure "config nmsp notification interval" followed by the specific type of device or metric, in this case, 'rssi rogues', and the desired interval time '5' seconds, sets the frequency of NMSP notifications for RSSI updates related to rogue devices.
References := ( CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide )