[CMake] CMake for PS2

[Mathias Lafeldt]

I'm currently developing CMake scripts to support the PS2 console:
http://bitbucket.org/misfire/cmake-ps2/src/

FYI, the PS2 has two processors:
- EE (Emotion Engine, 64-bit MIPS-III R5900) and
- IOP (I/O processor, 32-bit MIPS-I R3000)

There's a working toolchain including ee-gcc, iop-gcc, binutils, etc.
and a homebrew PS2SDK.

I already got more or less working CMake scripts for EE including a
toolchain and a platform system file. But actually, I'm a little bit
confused about the exact usage of those files.

I know that the platform file belongs to Modules/Platform/ and is
automatically loaded depending on CMAKE_SYSTEM_NAME. But what about the
toolchain file? It looks like they aren't part of the CMake package.

-Mathias