The reason for the :=? operator was for when you have an adapter chain
whose direction of cardinality you could not know. We used explicit
directives to tell these compositions which way to go.
Unfortunately, that makes the API leaky. You think the chain of adapters
is just one adapter, but you have to use strange Cardinality scopes to
use it. That's just bad.
The new :*=* just automagically figures it out from the graph.
There is a buffer on the sbus backside.
There is a buffer on the pbus frontside.
Between them is only an AtomicAutomata.
That should be enough for most designs.
* coreplex collapse: peripherals now in coreplex
* coreplex: better factoring of TLBusWrapper attachement points
* diplomacy: allow monitorless :*= and :=*
* rocket: don't connect monitors to tile tim slave ports
* rename chip package to system
* coreplex: only sbus has a splitter
* TLFragmenter: Continuing my spot battles on requires without explanatory strings
* pbus: toFixedWidthSingleBeatSlave
* tilelink: more verbose requires
* use the new system package for regression
* sbus: add more explicit FIFO attachment points
* delete leftover top-level utils
* cleanup ResetVector and RTC
