LinuxKPI: 802.11: remove lkpi_iv_key_set/delete wrappers

We currently use simple wrapper functions not doing anything for
lkpi_iv_key_set/delete. Garbage collect them and call the
implementation directly.

Sponsored by: The FreeBSD Foundation

(cherry picked from commit aa294e8e40a1aa93d5af05d573744833c5f6804a)