Blocks should be synchronized on read-only fields (#5212)

* Blocks should be synchronized on read-only fields

* more readonlys

* fix alignment

* more

* Update ISelfController.cs

* simplify new

* simplify new

src/Ryujinx.SDL2.Common/SDL2Driver.cs

@@ -41,7 +41,7 @@ namespace Ryujinx.SDL2.Common
 
         private ConcurrentDictionary<uint, Action<SDL_Event>> _registeredWindowHandlers;
 
-        private object _lock = new object();
+        private readonly object _lock = new();
 
         private SDL2Driver() {}