or1k: Some first work in re-implementing stuff

I started to put some first stuff together, namely adapted Makefiles and the syscalls from libnosys.
or1k: Support for cores without delay slot
or1k: Bring in old work and restructure
Board cleanup.
More livensing cleanup.

impure stuff was rewritten, sbrk is copied, caches from julius
identation fix
Fix missing libgloss
Replace spr-defs with BSD version

Replace with auto-generated or1k-sprs.h from or1k-headers project.
Update SPR definitions for assembly
Add interrupt enable and disable
Add mfspr and mtspr
Reentrancy back in again
Replace static nop number with definition from or1k-headers
Add XUPV5 board
All boards to exit the simulator

This patch was proposed by Matthew Hicks (firefalcon@gmail.com). His
patch pushed the exit nop in the delay slot or as part of the loop
respectively. This may not be desired for multicore configurations or
similar.
Add missing header
Add timer functions and update SPRs
Finish work on reentrancy
Add convenience functions for critical sections
Correct syscall header and code beautification