RDMA/erdma: Add GID table management interfaces

The erdma_add_gid() interface inserts a GID entry at the
specified index. The erdma_del_gid() interface deletes the
GID entry at the specified index. Additionally, programs
can invoke the erdma_query_port() and erdma_get_port_immutable()
interfaces to query the GID table length.

Signed-off-by: Boshi Yu <boshiyu@linux.alibaba.com>
Link: https://patch.msgid.link/20241211020930.68833-3-boshiyu@linux.alibaba.com


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