Philippe Gerum authored Feb 20, 2021 and Jan Kiszka committed Mar 08, 2021

In order to intimately connect Cobalt to the kernel, Dovetail allows
us to extend the latter with data and procedures we need:

- we can embed our own context information into a set of critical
  kernel data structures. This information should be defined as a set
  of core-specific types, such as struct oob_thread_state which is
  going to be part of struct thread_info.

- we can define preparation and finalization handlers for out-of-band
  IRQ handling, which Dovetail should invoke right after entering the
  outer interrupt frame, then right before leaving it respectively.

Add the couple of interface headers we need to connect those elements
to the kernel.

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>