rdma: Add resource tracking summary

rdma: Add resource tracking summary

The global resource summary information. The object names, current utilization
and maximum numbers are received as is from the kernel.

$ rdma res
1: mlx5_0: pd 3 cq 5 qp 4
2: mlx5_1: pd 3 cq 5 qp 4
3: mlx5_2: pd 3 cq 5 qp 4
4: mlx5_3: pd 2 cq 3 qp 2
5: mlx5_4: pd 3 cq 5 qp 4

$ rdma res show mlx5_4
5: mlx5_4: pd 3 cq 5 qp 44

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>