Remove deprecated -no-frame option

The -no-frame option has been deprecated with QEMU v2.12. It was only
useful with SDL1.2 - now that we've removed support for SDL1.2, we
can certainly remove the -no-frame option, too.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-id: 1549351769-19620-1-git-send-email-thuth@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>