LinuxKPI: add time_is_before_jiffies()

Add time_is_before_jiffies() as needed by iwlwifi from v6.11.

Sponsored by: The FreeBSD Foundation
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D46841

(cherry picked from commit 8f9567628cb2ccb335640c4bb044df2ebf45d83a)