Add initial prototype.

3-mid/opengl/source/platform/egl/private/opengl-surface_profile-privvy.adb

@@ -0,0 +1,10 @@
+package body opengl.surface_Profile.privvy
+is
+
+   function to_eGL (Self : in Item'Class) return egl.EGLConfig
+   is
+   begin
+      return Self.egl_Config;
+   end to_eGL;
+
+end opengl.surface_Profile.privvy;