Disable LPF filtering in new-ax-hle

The current implementation is broken and this is a non critical feature.

Fixes new-ax-hle regression in Super Monkey Ball.

Source/Core/Core/Src/HW/DSPHLE/UCodes/UCode_AX_Voice.h

@@ -457,7 +457,9 @@ void ProcessVoice(PB_TYPE& pb, const AXBuffers& buffers, u16 count, AXMixControl
 	}
 
 	// Optionally, execute a low pass filter
-	if (pb.lpf.enabled)
+	// TODO: LPF code is currently broken, causing Super Monkey Ball sound
+	// corruption. Disabled until someone figures out what is wrong with it.
+	if (0 && pb.lpf.enabled)
 	{
 		pb.lpf.yn1 = LowPassFilter(samples, count, pb.lpf.yn1, pb.lpf.a0, pb.lpf.b0);
 	}