refactor: Some vita optimizations

[Pazaz]

Just some ideas I had.

1. Thread affinities pinned to separate cores

• Game Loop thread (core 0)
• vitaGL garbage collection thread (core 1)
• Game Audio thread (core 2)

2. SceTouchPanelInfo is always the same so it's now cached on startup
3. No MSAA for vitaGL so it's as sharp as CPU rendering
4. Disabled vitaGL Vblank since at best it hurts performance here
5. (fix) It appears that glViewport is simply a transform, it doesn't set rasterization bounds. glScissor is needed on vita or it overdraws
6. Optimized the PixMap drawing loops. The viewport test advances 4 pixels at once, and the dirty loop can optimize into SIMD to draw 4-16 pixels at once (4 on vita, 16 on macOS). 5-6 ms becomes 1-2 ms

More significant vita gains will have to come improving from the GL backend. Hotspots are World3D and the minimap.

[lesleyrs]

Agreed with all changes, thanks