Add a new module `kernel::interop::list` for working with C's doubly
circular linked lists. Provide low-level iteration over list nodes.

Typed iteration over actual items is provided with a `clist_create`
macro to assist in creation of the `CList` type.

Cc: Nikola Djukic <ndjukic@nvidia.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Gary Guo <gary@garyguo.net>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Link: https://patch.msgid.link/20260319210722.1543776-1-joelagnelf@nvidia.com
[ * Remove stray empty comment and double blank line in doctest,
  * Improve wording and fix a few typos,
  * Use markdown emphasis instead of caps,
  * Move interop/mod.rs to interop.rs.

    - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>