Remove zerogs and zerospu2 from master branch

[lightningterror]

No description provided.

[arcum42]

Main thing that stands out is in GameIndex.dbf:

Serial = PBPX-95506
Name   = Playstation 2 - Demo Disc 2001
Region = PAL-M5
[patches]
	// 7ACF7E03
	comment=You must enable the EETimingHack when playing the WRC demo to avoids random hangs.
	comment=You must change the EE Clamping mode to Full when playing the Klonoa 2 demo to avoids misplaced objects.
	comment=You must change the VU Clamping mode to extra when playing the Klonoa 2 demo to fixes reflections issues.
	comment=You must use the ZeroSPU2 plugin when playing the Klonoa 2 demo to avoids bad/missing sounds.
[/patches]

We probably shouldn't be recommending a plugin we're removing. Is that even true any more?

[arcum42]

Yes. I didn't see any reason to get rid of them. For example, ZeroSPU2 no longer being there doesn't mean that Alsa.cpp is no longer based on code from it...

[arcum42]

On the dummy function, I'd just be worried about breaking something inadvertently when deleting it, so I'd tend towards having getting rid of that be a separate commit and not mixed into this pr.

And on the registers comment, if I was touching that code, I'd rather have the historical context there, so I knew why things had been handled that way previously.

[lightningterror]

Yeah I left all those on purpose for those reasons.

[arcum42]

Think we're probably fine, then.