vdpa/mlx5: prepare HW queues

vdpa/mlx5: prepare HW queues

As an arrangement to the vitrio queues creation, a 2 QPs and CQ may be
created for the virtio queue.

The design is to trigger an event for the guest and for the vdpa driver
when a new CQE is posted by the HW after the packet transition.

This patch add the basic operations to create and destroy the above HW
objects  and to trigger the CQE events when a new CQE is posted.

Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>