Refactor SVC handler (#540)

* Refactor SVC handler

* Get rid of KernelErr

* Split kernel code files into multiple folders

Ryujinx.HLE/HOS/Kernel/Process/KHandleEntry.cs

@@ -0,0 +1,17 @@
+namespace Ryujinx.HLE.HOS.Kernel.Process
+{
+    class KHandleEntry
+    {
+        public KHandleEntry Next { get; set; }
+
+        public int Index { get; private set; }
+
+        public ushort HandleId { get; set; }
+        public object Obj      { get; set; }
+
+        public KHandleEntry(int index)
+        {
+            Index = index;
+        }
+    }
+}