RDMA: Extend RDMA kernel ABI to support atomic write

1) Define new atomic write request/completion in kernel.
2) Define new atomic write capability in kernel.
3) Define new atomic write opcode for RC service in packet.

Link: https://lore.kernel.org/r/1669905432-14-3-git-send-email-yangx.jy@fujitsu.com


Signed-off-by: Xiao Yang <yangx.jy@fujitsu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>