RDMA/erdma: Support non-sleeping erdma_post_cmd_wait()

RDMA/erdma: Support non-sleeping erdma_post_cmd_wait()

Several scenarios require posting commands to the cmdq in a non-sleepable
context. For example, the cm_alloc_msg() might call erdma_create_ah()
while still holding a spinlock. So we add support for non-sleeping
erdma_post_cmd_wait().

Reviewed-by: Cheng Xu <chengyou@linux.alibaba.com>
Signed-off-by: Boshi Yu <boshiyu@linux.alibaba.com>
Link: https://patch.msgid.link/20241226084141.74823-4-boshiyu@linux.alibaba.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>