Begin working on cpukit code. Create necessary cpukit../cpu/or1k../score
files to handle types, context switches, processor configurations, and
other features. This commit includes header files additions/changes.
Some code (back from 2005) is no longer valid, so it had to be deleted.
cpukit library can not compile now (cpu.c) because of the previous deletion.

TODO: re-define processor macros according to the latests or1k architecture
and implement all necessary functions following modern conventions for
similar architectures like arm, moxie, and nios2.