Refactor SVC handler (#540)

* Refactor SVC handler

* Get rid of KernelErr

* Split kernel code files into multiple folders

Ryujinx.HLE/HOS/Kernel/Memory/MemoryRegion.cs

@@ -0,0 +1,10 @@
+namespace Ryujinx.HLE.HOS.Kernel.Memory
+{
+    enum MemoryRegion
+    {
+        Application = 0,
+        Applet      = 1,
+        Service     = 2,
+        NvServices  = 3
+    }
+}