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

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

ath(4) IfAPI fixups

Use the if_getcounter() IfAPI instead of accessing the ifnet directly.

Sponsored by: Juniper Networks, Inc.

DrvAPI: Trivial mechanical conversions for various drivers

Mechanically convert the following drivers, with trivial changes:
* ipw(4)
* igc(4)
* enetc(4)
* malo(4)
* nfe(4)
* bxe(4)
* awg(4)
* otus(4)
* rtwn(4)
* bnxt(4)
* ath(4)

Sponsored by: Juniper Networks, Inc.

ath: clean up empty lines in .c and .h files

Use an accessor function to access ifr_data.

This fixes 32-bit compat (no ioctl command defintions are required
as struct ifreq is the same size). This is believed to be sufficent to
fully support ifconfig on 32-bit systems.

Reviewed by: kib
Obtained from: CheriBSD
MFC after: 1 week
Relnotes: yes
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14900

ath: fix possible memory disclosure in ioctl handler

Submitted by: Domagoj Stolfa <domagoj.stolfa@gmail.com>
MFC after: 1 week

ath: revert accidental change committed with r327526

It will be recommitted with the correct commit message.

embed_mfs: correctly test grep return value

Reported by: br
MFC with: r326992
Sponsored by: The FreeBSD Foundation

[ath] Begin to lay the groundwork for btcoex related ioctl controls.

dev/ath: minor spelling fixes in comments.

No functional change.

Reviewed by: adrian

[ath] migrate ioctl and busdma memory operations out into separate source files.

This should be a big no-op pass; and reduces the size of if_ath.c.

I'm hopefully soon going to take a whack at the USB support for ath(4)
and this'll require some reuse of the busdma memory code.