[FEATURE] SMB2/3 support

[sahlberg]

I would like to propose adding https://github.com/sahlberg/libsmb2 to the ps2sdk-ports build.

What is libsmb2?
Libsmb2 is a small footprint, high performance, smb2/3 client that compiles for almost any platform that has BSD socket support.
It supports SMB2 all the way up to SMB3.1.1, including signing, encryption and a dcerpc layer.
It is used by both vlc and kodi for all the platforms they build on (linux, bsd, windows, macos, iOS, android, xbox, ...) and is fairly feature complete and mature.
It it interoperates with all smb2 capable servers I have access to, including Windows, Samba, MacOS, EMC, NetApp, ksmb3d (linux kernel smb server), Microsoft Azure ...

I recently ported it to build with ps2sdk and have used it for some test applications on a slim ps2.
I think it would be really useful for many types of applications for ps2 to have access to a modern and high quality smb2/3 client, especially file managers.

The repository is https://github.com/sahlberg/libsmb2 and I have merged the support for PS2 EE into the master branch.
To build :
$ cd lib
$ make -f Makefile.PS2_EE
then copy the resulting libsmb2.a library and the public header files from include/smb2 into your project.

You want your PS2 to be able to access a file share in Microsoft Azure ? It can happen. And it will be epic.