uae: a game requiring empty input port found

see #4213

src/BizHawk.Emulation.Cores/Computers/Amiga/LibUAE.cs

@@ -90,6 +90,7 @@ namespace BizHawk.Emulation.Cores.Computers.Amiga
 
 		public enum ControllerType : int
 		{
+			None,
 			Joystick,
 			Mouse,
 			[Display(Name = "CD32 pad")]

src/BizHawk.Emulation.Cores/Computers/Amiga/UAE.ISettable.cs

@@ -264,6 +264,9 @@ namespace BizHawk.Emulation.Cores.Computers.Amiga
 
 				switch (type)
 				{
+					case LibUAE.ControllerType.None:
+						AppendSetting($"joyport{port}=none");
+						break;
 					case LibUAE.ControllerType.Joystick:
 						AppendSetting($"joyport{port}mode=djoy");
 						break;

waterbox/uae/bizhawk.c

@@ -48,6 +48,8 @@ ECL_EXPORT void FrameAdvance(MyFrameInfo* f)
 	for (int port = 0; port <= 1; port++)
 	{
 		Controller *controller = (port == 0) ? &f->Port1 : &f->Port2;
+		if (controller->Type == CONTROLLER_NONE) continue;
+		
 		cd32_pad_enabled[port] = 0;
 		joydir[port] = 0;
 

waterbox/uae/bizhawk.h

@@ -93,6 +93,7 @@ enum DriveAction
 
 enum ControllerType
 {
+	CONTROLLER_NONE,
 	CONTROLLER_JOYSTICK,
 	CONTROLLER_MOUSE,
 	CONTROLLER_CD32PAD