hw/virtio: derive vhost-user-input from vhost-user-base

hw/virtio: derive vhost-user-input from vhost-user-base

This patch derives vhost-user-input from vhost-user-base class, so make
the input stub as a simpler boilerplate wrapper.

With the refactoring, vhost-user-input adds the property 'chardev', this
leads to conflict with the vhost-user-input-pci adds the same property.
To resolve the error, remove the duplicate property from
vhost-user-input-pci.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Message-Id: <20231120043721.50555-5-leo.yan@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240104210945.1223134-12-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>