Instead of hosting our outdated own fork, this commit now uses kernkonzept's
nowadays available github source repositories. This hopefully simplifies
updates, or cherry-picking single fixes.
Removes the following Fiasco.OC specific features:
* GDB extensions for Fiasco.OC
* i.MX53 support for Fiasco.OC
* Kernel debugger terminal driver
* Obsolete interface Native_pd
* Obsolete function of interface Native_cpu
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082