Remove dependency on qiochannel by removing yank_generic_iochannel and
letting migration and chardev use their own yank function for
iochannel.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20ff143fc2db23e27cd41d38043e481376c9cec1.1616521341.git.lukasstraub2@web.de>

The yank feature allows to recover from hanging qemu by "yanking"
at various parts. Other qemu systems can register themselves and
multiple yank functions. Then all yank functions for selected
instances can be called by the 'yank' out-of-band qmp command.
Available instances can be queried by a 'query-yank' oob command.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <69934ceacfd33a7dfe53db145ecc630ad39ee47c.1609167865.git.lukasstraub2@web.de>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>