sys: Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

iwm(4): Remove _mvm from the namespace.

This was inherited from iwlwifi, which drives devices supported by both
iwn(4) and iwm(4) in FreeBSD. In iwm(4) _mvm is meaningless, so remove
it. OpenBSD made the same change a long time ago. No functional change
intended.

MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation

[iwm] Adjust if_iwm_sta.h prototypes, don't pass iwm_node to rm_sta().

* Since a RUN -> INIT/SCAN transition seems to immediately destroy the
ieee80211_node for the AP, we can't read the in_assoc value from there.
Instead just directly pass that information via a boolean_t argument.

* Adds iwm_mvm_rm_sta_id() function, which just unconditionally removes
the station from the firmware.

* The iwm_mvm_rm_sta() function shouldn't actually remove the station from
firmware when we are still associated (i.e. during a RUN -> INIT/SCAN
transition).

* So when disassociating we will first call iwm_mvm_rm_sta() to drain the
queues/fifos. Later during disassociation we will then use
iwm_mvm_rm_sta_id() to actually remove the station.

Inspired-By: Linux iwlwifi

Obtained from: dragonflybsd.git 81b3c1fe9122fa22f33d97103039cc375f656231

[iwm] Factor out firmware station handling into if_iwm_sta.c.

* This adds iwm_mvm_rm_sta(), which will be used to tear down firmware
state for better/cleaner iwm_newstate() handling.

* Makes iwm_enable_txq() and iwm_mvm_flush_tx_path() non-static, add
the declarations to if_iwm_util.h for now.

Obtained from: dragonflybsd.git 85d1c6190c4c3564b1a347f253e823aa95c202b2