rdma: Add CQ resource tracking information

rdma: Add CQ resource tracking information

Sample output:

# rdma resource show cq
dev cxgb4_0 cqe 46 users 2 pid 30503 comm rping
dev cxgb4_0 cqe 46 users 2 pid 30498 comm rping
dev mlx4_0 cqe 63 users 2 pid 30494 comm rping
dev mlx4_0 cqe 63 users 2 pid 30489 comm rping
dev mlx4_0 cqe 1023 users 2 poll_ctx WORKQUEUE pid 0 comm [ib_core]

# rdma resource show cq pid 30489
dev mlx4_0 cqe 63 users 2 pid 30489 comm rping

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: David Ahern <dsahern@gmail.com>