While looking through the source, I realised there was a target named bmips and another target named bcm63xx. I would've presumed from the target descriptions that bcm63xx was only for those chips, with a DSL core, and bmips covered all others (namely, bcm33xx with DOCSIS modem).
Then I realised the bcm3368 is under the bcm63xx target? What's the deal with that? And there's also some DTS files duplicated under both targets?
Thank you for the response. I should probably have checked git before posting.
Am I also correct in presuming that bcm63xx (and bcm47xx) will be deprecated sooner rather than later, and therefore any new devices should be added under the new bmips target instead?