Add support for KVM_REINJECT_CONTROL ioctl on x86_64

[karuboniru]

This commit introduces support for the KVM_REINJECT_CONTROL VM ioctl on x86_64, along with a convenience method disable_pit_reinjection on VmFd for easier management of PIT reinjection settings.

Summary of the PR

Enable user to disable PIT reinjection, which accoding to kernel doc should be always set when possible.

pit_reinject = 0 (!reinject mode) is recommended, unless running an old operating system that uses the PIT for timing (e.g. Linux 2.4.x).

This will help fixing containers/libkrun#498

Requirements

Before submitting your PR, please make sure you addressed the following
requirements:

• All commits in this PR have Signed-Off-By trailers (with
  git commit -s), and the commit message has max 60 characters for the
  summary and max 75 characters for each description line.
• All added/changed functionality has a corresponding unit/integration
  test.
• All added/changed public-facing functionality has entries in the "Upcoming
  Release" section of CHANGELOG.md (if no such section exists, please create one).
• Any newly added unsafe code is properly documented.

[roypat]

I guess we need a #[allow(confusable_idents)] in the bindings.rs files. What the hell even is that lint 😒