SPE Support

[Joel Sherrill]

Hi

Just thinking out loud.

If the SPE continues to be supported by GCC, why can't we just have
spe as a separate CPU in the tree with all the build infrastructure
just reference PowerPC files as needed in their current location?

I can see a need to copy/move a bsp.h and perhaps,
score/cpu/spe/include would have to be populated.

Just thinking there has to be a relatively straightforward hack to
make this work.

--joel