RDMA/erdma: Implement atomic operations support

Add atomic operations support in post_send and poll_cq implementation.
Also, rename 'laddr' and 'lkey' in struct erdma_sge to 'addr' and 'key',
because this structure is used for both local and remote SGEs.

Signed-off-by: Cheng Xu <chengyou@linux.alibaba.com>
Link: https://lore.kernel.org/r/20221107021845.44598-4-chengyou@linux.alibaba.com


Signed-off-by: Leon Romanovsky <leon@kernel.org>