Use CMake for compiling some libraries

[fjtrujy]

Description

This PR basically use CMake to compile some ports without any additional change (thanks @rickgaiser for the idea).

The libraries being compiled with CMake are:

• zlib
• libpng
• freetype2

Additionally, I have also added:

• yaml

All these libraries were previously git submodules, and it was creating more issues than adventages, so now they are downloaded using git clone to a build folder.

The cmake file used for the compilation is being copied as well to the toolchain, so it will be available at: $(PS2SDk)/ps2dev.cmake, so you can use that file for compile easily other projects.

Finally, I have also improved the CI and the scrips using the available cores during compilation, making the compilation shorter.

PS: I have also removed from git submodules the libtap library and now it is also using git clone

Thanks

[rickgaiser]

The git submodules where always trouble for me, so thank you for this. Only 2 things:

• FreeType: I think we're now building the default freetype again, without any configuration. The changes made in #45 will be undone by this PR? (See also #35)
• libtap: still using git submodules, so now we have 2 systems to fetch other git projects, can this last git submodule also be removed?

[fjtrujy]

So about freetype I'm not really sure, but I think that something changed since that date.

This is the size with the legacy toolchain

This is the size with the new toolchain, but using the custom compilation

And this is the size of the library using the generic compilation and cmake

I didn't check what's the final OPL result, but I don't expect bigger than before LOL

About libtap I just migrate to git clone the libraries used with cmake, I can migrate libtap as well from git submodules to git clone, is up to you.

Thanks

[fjtrujy]

Actually, I have just updated freetype to the new official git and the latest version available as well. Still 13kb less than the previous implementation.

[fjtrujy]

@rickgaiser I have removed libtap as well from the submodules!

Take a look