[VirtLayer] Changes to the interrupt handling in POK

[Philipp Eppelt]

Hi,

lately I worked a lot to extend POK with necessary features to
accommodate an RTEMS partition.
Since hello world works, I need a way to pass clock ticks to the RTEMS
partition running on POK. Therefore the interrupt handling needs to
support custom handlers.

If everything works out, I can enable the virtualization layer to
register an interrupt vector and if it occurs RTEMS is notified by
invoking C_dispatch_isr().

Blog:
http://phipse.github.io/rtems/blog/2013/08/17/pok-hardware-interrupt-handling/

Source:
https://github.com/phipse/pok

Cheers,
Philipp