Switch to -m4-single

[MastaG]

I can confirm that it fully builds everything.
However do not merge it until I have tested it later this week.

[MastaG]

@DC-SWAT I didn't find any regressions building with -m4-single instead of -m4-single-only.
Perhaps just leave this open until KOS switches to -m4-single by default, then we can merge it.
This way we can stay as close to KOS defaults as possible.

[MastaG]

I have did lots of testing and couldn't find any stability problems with this PR.
The crashes at the games menu are also there without my PR, it's still WIP.
Same goes for the crash when entering and exiting the "GD Play" menu without any disc inserted.

[DC-SWAT]

I think it's worth waiting for KOS to switch to this by default. Because I try to keep the code as close to the default KOS as possible.
Also I was told that this mode will not be removed from the GCC.

[MastaG]

absolutely, I just wanted to mention that I couldn't find any issues.
I will rebase this once kos switches.