the device manager is initialized. For x86 it does nothing, but
for PPC it searches for a supported interrupt controller and
remembers it for later use.
arch_int_{enable,disable}_io_interrupt() are implemented as
well as handling of external exceptions (aka as I/O interrupts).
We'll see later how well that works.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16271 a95241bf-73f2-0310-859d-f6bbb57e9c96