Add source / sink modules for replication for error detection.

[Lynx005F]

This PR adds two modules to "copy" a HCI stream so that a secundary HCI network can be built for error detection on both control and data. These modules can work together with similar modules for HWPE-Stream, where the Idea is explained more in detail pulp-platform/hwpe-stream#21

Currently the PR only implements the "copy" variety (see HWPE PR for definition) of replication modules. For the redundancy in RedMulE this is the only module required.
If the other varieties could be usefull elsewhere I could implement them as well, but since they would result in different parameterizations of HCI for the copy network as existing modules would have to be looked at too, while copy is "safe" with respect to other modules.

[Lynx005F]

I merged all different options into one file and added a type selection enum. Potentially there are other types of duplication that could also be implemented, but for RedMulE this covers everything needed.

[LuigiGhionda]

LGTM

[FrancescoConti]

@anga93 @LuigiGhionda @yvantor is this still relevant?

[LuigiGhionda]

I think it is only used inside Fault-Tolerant Redmule, which, if I’m not mistaken, is still maintained in an external fork outside of pulp-platform. I’m not sure if there has been any additional development since then. From the HCI fork, I’ve noticed some activity, so there might be something new to add. Perhaps @Lynx005F can confirm this.

[Lynx005F]

Yes this is still used in Redundant RedMulE, but only one of the two modules:
https://github.com/Lynx005F/redmule/blob/itemm/redundancy/rtl/redmule_top.sv#L211
I think it makes sense having both sides of it anyway, should be the easiest way to get control protection elsewhere.

As far as that project is concerned the project is completed and achieves good fault-tolerance.
If there are future changes then only to increase performance, which should not affect these modules.

[FrancescoConti]

I agree, I think it is a valuable contribution, thank you @Lynx005F ! @LuigiGhionda can you give again a very quick look (a lot of time has passed since your review)? I will also review, and if ok, we'll merge.

[FrancescoConti]

very minor: hci_core_assign -> hci_copy_source

[FrancescoConti]

LGTM