IB/rdmavt: Add __init/__exit annotations to module init/exit funcs

Add missing __init/__exit annotations to module init/exit funcs.

Fixes: 0194621b ("IB/rdmavt: Create module framework and handle driver registration")
Link: https://lore.kernel.org/r/20220924091457.52446-1-xiujianfeng@huawei.com


Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>