sys: Remove $FreeBSD$: one-line sh pattern

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

ath10k: ath11k: add specific LinuxKPI support

Add files needed by ath1?k drivers to linuxkpi/linuxkpi_wlan.
This contain (skeleton) implementations of what is needed to
compile but specifically mhi/qmi/qrtr will need more work for
ath11k.

MFC after: 2 months

LinuxKPI: define LINUXKPI_INCLUDES for module builds as well

While for in-kernel we already have LINUXKPI_INCLUDES in kern.pre.mk
for kmod builds we've not had a common define to use leading to various
spellings of include paths.

In order for the include list to be expanded more easily in the future,
e.g., adding the "dummy" includes (for all) and to harmonize code,
duplicate LINUXKPI_INCLUDES to kmod.mk and use it for all module Makefiles.

MFC after: 1 week
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D36683

LinuxKPI: add 802.11 compat code

Add 802.11 compat code for mac80211 and to a minimal degree cfg80211.
This allows us to compile and use basic functionality of wireless
drivers such as iwlwifi.

This is a constant work in progress but having it in the tree will
allow others to test and more easy to track changes and avoid having
snapshots no longer applying to branches.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days