[retro-gtk] core-view: Add missing license header

[Adrien Plazas <aplazas src gnome org>]

commit 1d2c63e2872066d704db23547067d22b4049fa47
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Thu Oct 12 08:19:06 2017 +0200

    core-view: Add missing license header

 retro-gtk/retro-core-view.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/retro-gtk/retro-core-view.h b/retro-gtk/retro-core-view.h
index ed7892d..737fbd1 100644
--- a/retro-gtk/retro-core-view.h
+++ b/retro-gtk/retro-core-view.h
@@ -1,3 +1,5 @@
+// This file is part of retro-gtk. License: GPL-3.0+.
+
 #ifndef RETRO_CORE_VIEW_H
 #define RETRO_CORE_VIEW_H