runq: Re-order functions more logically
No code change in moved functions.
Reviewed by: kib
MFC after: 1 month
Event: Kitchener-Waterloo Hackathon 202506
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D45387
(cherry picked from commit 200fc93dace76cf251460adc58ca809c36031f3e)