RDMA/erdma: Refactor the code of the modify_qp interface

The procedure for modifying QP is similar for both the iWARP and
RoCEv2 protocols. Therefore, we unify the code and provide the
erdma_modify_qp() interface for both protocols.

Signed-off-by: Boshi Yu <boshiyu@linux.alibaba.com>
Link: https://patch.msgid.link/20241211020930.68833-7-boshiyu@linux.alibaba.com


Reviewed-by: Cheng Xu <chengyou@linux.alibaba.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>