[Request] Expose ibv_advise_mr

[yinghai]

ibv_advise_mr is quite useful in some usecases but currently it's static inline in verbs.h (https://github.com/linux-rdma/rdma-core/blob/76a7321311b131fe12787b2dad4bb0c113897dbb/libibverbs/verbs.h#L2731). It would be nice to expose the rust binding to it. I think there can be 2 options.

1. Follow How to handle `static inline` functions rust-lang/rust-bindgen#2405. I tested locally and it seems to work. It will expose all the static inline symbols though.
2. Expose verbs_context(https://github.com/linux-rdma/rdma-core/blob/76a7321311b131fe12787b2dad4bb0c113897dbb/libibverbs/verbs.h#L2139) in the allow list. And we can add some rust code to implement the equivalent of ibv_advise_mr (e.g. https://github.com/RDMA-Rust/rdma-mummy-sys/blob/45d16c6f012d8753b8dab6d08ac323cb8528f74c/src/verbs.rs#L471-L485). This will give user more control on what they want to do.

I think either is fine. But having that option to use ibv_advise_mr would be cool.