SCCC (SCC Context) is a context with QP granularity that contains
information about congestion control. Dump SCCC and QPC together
to improve troubleshooting.

When dumping raw QPC with rdmatool, there will be a total of 576 bytes
data output, where the first 512 bytes is QPC and the last 64 bytes is
SCCC. When congestion control is disabled, the 64 byte SCCC will be all 0.

Example:
$rdma res show qp -jpr
[ {
        "ifindex": 0,
        "ifname": "hns_0",
	"data": [ 67,0,0,0... 512bytes
		  4,0,2... 64bytes]
  },...
} ]
Signed-off-by: wenglianfa <wenglianfa@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20240305055257.823513-1-huangjunxian6@hisilicon.comSigned-off-by: Leon Romanovsky <leon@kernel.org>