rdma: Add support to get QP in raw format

rdma: Add support to get QP in raw format

Add 'raw' argument to get the resource in raw format.
When RDMA_NLDEV_ATTR_RES_RAW is set in the netlink message,
then the resource fields are in raw format, print it as byte array.

Example:
$rdma res show qp link rocep0s12f0/1 lqpn 1137 -j -r
[{"ifindex":7,"ifname":"mlx5_1","port":1,
"data":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,...]}]

Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: David Ahern <dsahern@kernel.org>