Rename Ryujinx.Core to Ryujinx.HLE and add a separate project for a future LLE implementation

Ryujinx.HLE/OsHle/Kernel/NsTimeConverter.cs

@@ -0,0 +1,19 @@
+namespace Ryujinx.HLE.OsHle.Kernel
+{
+    static class NsTimeConverter
+    {
+        public static int GetTimeMs(ulong Ns)
+        {
+            ulong Ms = Ns / 1_000_000;
+
+            if (Ms < int.MaxValue)
+            {
+                return (int)Ms;
+            }
+            else
+            {
+                return int.MaxValue;
+            }
+        }
+    }
+}