virtio_remoteproc: correct put_device virtio_device.dev

rproc_virtio_dev_release will be called iff virtio_device.dev's
reference count drops to 0. Here we just put vdev.dev, and then
rproc->dev's cleanup will be done in rproc_virtio_dev_release.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>