This dependency is currently "automagic", which is bad for distributions.

Signed-off-by: James Le Cuirot <chewi@gentoo.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20190914145155.19360-1-chewi@gentoo.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>