Add basic stubs and files to build the new or1k BSP: or1ksim.
This is not meant to be upstreamed, it's just some trials that may
help, in the time being, in debugging bare-metal applications and minimal
basic infrastructure for or1k architecture. However, it can be
a starting point when moving to RTEMS porting task.
The following are major changes:

+cpukit/cpu: added or1k cpu, some files are borrowed and modified
from the old or32 port. Stubs, definitions and changes made to be
able to build libraries and move to bsp.

+libbsp/or1k: Minimal configuration for adding new or1k/or1ksim
BSP. This bsp only has start.S which do nothing other than calling
main. It's provided to make sure that libbsp.a is generated when
building RTEMS for or1k.
Begin first steps for implementing or1ksim BSP, start.S and linkcmds follow much of of the ARM code
Add linker-symbols.h to Makefile.am
preinstall.am files for or1k BSP(s)
preinstall.am for cpukit
Fix a bug at linkcmds. Delete all variables at start.S and use linker-symbols instead. Add clear .bss to start.S _start function
Fix doxygen documentation error
Add console driver for or1ksim BSP
Edit lincmds to include TLS and other rodata sections
Console driver is tested (without multi-tasking).
Initial version of Clock driver.
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Some code (back from 2005) is no longer valid, so it had to be deleted.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.
Add necessary implementations to cpukit to get multi-tasking working.
Now, helloworld and ticker  samples are working on or1ksim.

The most important implementations are for context initialize and switch.
The code is to be refined and optimized later. Some bugs are fixed for clock
driver also.
- Avoid saving/restoring r10 as it's used by TLS.

- Optimize context switch to save/restore only preserved
registers across functions calls.

Conflicts:
	c/src/lib/libbsp/or1k/or1ksim/clock/clockdrv.c
Add initial stubs for implementing IRQ manager
Add default exception handler and print exception frame functions
Delete .swp file
Add or1k exception symbolic names
Add exception table in start.S file and make exceptions jump to
default exception handler as a default behavior at startup static
code. Dynamic handler can be installed at later stages of startup
process code.

Other bugs are solved too.
Implement ISR_Disable
Implement enable_isr function, rtems_exception_init and make it called
from bsp_start. Fix some other bugs.