Replace PULP cluster DMA

[alfiodm]

• Integrate the iDMA
• multi-initiator arbiter in HCI for full-bandwidth DMA access
• Write bare-metal tests

[FrancescoConti]

@arpansur @da-gazzi we can move the technical discussion here maybe... and link any PR e.g., in HCI for the multi-initiatior arbiter.

[FrancescoConti]

Also.. @adimauro-iis if an issue actually involves more than one repo, do we capture that here?

[alfiodm]

Good point, I like a lot the idea of associating an issues to specific code changes into a repo.

I think that whenever an issue requires changes into another repo we could:

1. Consider those changes as a pre-requisite for the issue, and assume they will be handled separately
2. Track them here, i.e. open an issue in the new repo and link it here as part of the task list, making them a sort of "sub-issue"

• Let's pretend this issue Produce a "nice" error when interfaces are improperly parametrized hci#42 is needed for our feature to be added

Option 2 tracks everything but require more diligence...I am fine with both

[DanielKellerM]

Enhancement implemented in #103 pending merge.