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

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

Add support for Intel 8265 WiFi

Obtained from: OpenBSD
MFC after: 1 month

[iwm] include opt_iwm.h and opt_wlan.h consistently in all files.

[iwm] Move struct iwm_cfg chipset configs to if_iwm_7000.c and _8000.c

* This is more similar to how code/definitions are distributed in
Linux's iwlwifi.

* This should make recognizing new chipset variants, and adding additional
flags from the Linux iwlwifi code easier, without blowing up if_iwm.c

Obtained from: dragonflybsd.git 27d11320e707d2c41424efc1983762f6799941d6