virtio-vdpa: add VIRTIO_F_NOTIFICATION_DATA feature support

Add VIRTIO_F_NOTIFICATION_DATA support for vDPA transport.
If this feature is negotiated, the driver passes extra data when kicking
a virtqueue.

A device that offers this feature needs to implement the
kick_vq_with_data callback.

kick_vq_with_data receives the vDPA device and data.
data includes:
16 bits vqn and 16 bits next available index for split virtqueues.
16 bits vqs, 15 least significant bits of next available index
and 1 bit next_wrap for packed virtqueues.

This patch follows a patch [1] by Viktor Prutyanov which adds support
for the MMIO, channel I/O and modern PCI transports.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Message-Id: <20230413081855.36643-3-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>