Improve kernel events implementation (#430)

* Improve kernel events implementation

* Some cleanup

* Address PR feedback

Ryujinx.HLE/HOS/Kernel/KWritableEvent.cs

@@ -0,0 +1,22 @@
+namespace Ryujinx.HLE.HOS.Kernel
+{
+    class KWritableEvent
+    {
+        private KEvent Parent;
+
+        public KWritableEvent(KEvent Parent)
+        {
+            this.Parent = Parent;
+        }
+
+        public void Signal()
+        {
+            Parent.ReadableEvent.Signal();
+        }
+
+        public KernelResult Clear()
+        {
+            return Parent.ReadableEvent.Clear();
+        }
+    }
+}