vl: use qmp_device_add() in qemu_create_cli_devices()

vl: use qmp_device_add() in qemu_create_cli_devices()

qemu_create_cli_devices() should use qmp_device_add() to match the
behavior of the QMP monitor. A comment explained that libvirt changes
implementing strict CLI syntax were needed.

Peter Krempa <pkrempa@redhat.com> has confirmed that modern libvirt uses
the same JSON for -device (CLI) and device_add (QMP). Go ahead and use
qmp_device_add().

Cc: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20240827192751.948633-3-stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>