port this for Playstation 2

[dirsors]

The ps2doom was made years ago and it was written for SDL 1.2.
Now, the current ps2toolchain runs SDL2 and ps2doom can't be updated to SDL2 without a lot of rework.
I propose a PS2 branch of this, using everything learned with the original ps2doom port at https://github.com/lukaszdk/ps2doom.