[PATCH 1/2] riscv: misaligned: Fix fast_unaligned_access_speed_key init

[Charlie Jenkins]

> When booting with unaligned_scalar_speed=fast,
> fast_unaligned_access_speed_key is initialized incorrectly.
> 
> The key is currently derived from the fast_misaligned_access cpumask, but
> that mask is only populated when the unaligned access speed probe runs.
> Specifying unaligned_scalar_speed=fast skips the probe entirely, leaving
> the mask uninitialized.
> 
> The information tracked by fast_misaligned_access is already available in
> the misaligned_access_speed per-CPU variable. Use that to initialize
> fast_unaligned_access_speed_key instead and remove the redundant cpumask.

Thanks for the fix. Looks good but needs to be rebased (apologies for
the delay on the review).

-- 
- Charlie