Merge tag 'rust-timekeeping-v6.18' of https://github.com/Rust-for-Linux/linux into...

Pull timekeeping updates from Andreas Hindborg:

 - Add methods on 'HrTimer' that can only be called with exclusive
   access to an unarmed timer, or form timer callback context.

 - Add arithmetic operations to 'Instant' and 'Delta'.

 - Add a few convenience and access methods to 'HrTimer' and 'Instant'.

* tag 'rust-timekeeping-v6.18' of https://github.com/Rust-for-Linux/linux:
  rust: time: Implement basic arithmetic operations for Delta
  rust: time: Implement Add<Delta>/Sub<Delta> for Instant
  rust: hrtimer: Add HrTimer::expires()
  rust: time: Add Instant::from_ktime()
  rust: hrtimer: Add forward_now() to HrTimer and HrTimerCallbackContext
  rust: hrtimer: Add HrTimerCallbackContext and ::forward()
  rust: hrtimer: Add HrTimer::raw_forward() and forward()
  rust: hrtimer: Add HrTimerInstant
  rust: hrtimer: Document the return value for HrTimerHandle::cancel()