rust: WMI abstractions

Overview
========
This patchset implements WMI abstractions for Rust drivers. It is the successor of the previous RFC posting [0]. These abstractions allow most WMI drivers to be implemented in Rust (provided other dependencies are abstracted as well).

Currently, the only driver in existance is a reference driver (rewrite of redmi-wmi, Armin is OK with that [1]). While being fully functional, it depends on sparse-keyboard abstractions, which I am still polishing. You can view WIP abstractions & driver at [2].

Notes
=====
I do not know how these abstractions should be handled in MAINTAINERS, so for now I have simply added them to the original WMI entry. I would be happy to be added as a reviewer to keep the Rust version 'synced'/valid though.

[0]: https://lore.kernel.org/rust-for-linux/[email protected]/
[1]: https://lore.kernel.org/rust-for-linux/[email protected]/
[2]: https://git.foxido.dev/foxido/linux/-/commits/rust_wmi?ref_type=heads

---
Changes since v1:
- Add lifetime to AcpiObject
- Add forgotten Sync requirement to the WMI driver trait
- Drop unsafe in DeviceId::new() (so no need for the const_intrinsic_copy feature)
- Device<Core> -> Device<Bound> in notify
- Small fixes (styling, missing safety comment)
- Add link to the WIP reference driver

I didn't touch AcpiObject::type_id() in v2 because it does its job for now. It's currently small (only one subtype, whereas both enum options would introduce a larger integration surface), and it would be an easy change if someone needs a more powerful solution.

I've also played around with some other suggestions, but:
- Suggested wrapping acpi_object instead of bindgen union subtypes will only introduce unneeded unsafety in each subtype's operation. I decided it's better to expose the bindgen type once than to validate a safety invariant each time.
- Suggested implementation via a sealed trait didn't really provide any benefits; it just raised code complexity a bit. Maybe I did it wrong, though...

Link to v1: https://lore.kernel.org/rust-for-linux/[email protected]/
---

Gladyshev Ilya (2):
rust: implement wrapper for acpi_object
rust: add WMI abstractions

 MAINTAINERS                     |   1 +
 rust/bindings/bindings_helper.h |   1 +
 rust/kernel/acpi.rs             |  97 +++++++++++
 rust/kernel/lib.rs              |   2 +
 rust/kernel/wmi.rs              | 286 ++++++++++++++++++++++++++++++++
 5 files changed, 387 insertions(+)
 create mode 100644 rust/kernel/wmi.rs

base-commit: 9ace4753a5202b02191d54e9fdf7f9e3d02b85eb

2.52.0