LinuxKPI: rename from_timer() to timer_container_of()

With Linux 6.16 from_timer() got renamed to timer_container_of(); add
the LINUXKPI_VERSION check with a default to the current version.
Update all in-tree consumers (apart from wireless drivers managed
otherwise).

Sponsored by: The FreeBSD Foundation (initially)
MFC after: 3 days
Reviewed by: dumbbell
Differential Revision: https://reviews.freebsd.org/D52073