RDMA/irdma: Move union irdma_sockaddr to header file

The union irdma_sockaddr is used frequently. So move it to the header
file.

Link: https://lore.kernel.org/r/20220223024252.3873736-4-yanjun.zhu@linux.dev


Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>