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.Input.SDL2/SDL2Keyboard.cs

@@ -24,7 +24,7 @@ namespace Ryujinx.Input.SDL2
             }
         }
 
-        private object _userMappingLock = new object();
+        private readonly object _userMappingLock = new();
 
         private readonly SDL2KeyboardDriver _driver;
         private StandardKeyboardInputConfig _configuration;