RDMA/hns: Remove redundant 'num_mtt_segs' and 'max_extend_sg'

mainline inclusion
from mainline-v6.1-rc1
commit 5436272c
category: cleanup
bugzilla: https://gitee.com/openeuler/kernel/issues/I7A4LC
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5436272c8cf4eb420fdb3926ec07560051c8fd11

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The num_mtt_segs and max_extend_sg used to be used for HIP06,
remove them since the HIP06 code has been removed.

Link: https://lore.kernel.org/r/20220922123315.3732205-9-xuhaoyue1@hisilicon.com


Signed-off-by: Yangyang Li <liyangyang20@huawei.com>
Signed-off-by: Haoyue Xu <xuhaoyue1@hisilicon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Zhou Juan <nnuzj07170227@163.com>
(cherry picked from commit c08f6dd3)