RDMA/hns: Fix wrong maximum DMA segment size

Set maximum DMA segment size to 2G instead of UINT_MAX due to HW limit.

Fixes: e0477b34 ("RDMA: Explicitly pass in the dma_device to ib_register_device")
Link: https://patch.msgid.link/r/20250327114724.3454268-3-huangjunxian6@hisilicon.com


Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>