sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

linuxkpi: Introduce module_param() of type `bint`

In Linux, this limits the accepted value to -1, 0 and 1.
In FreeBSD, this remains a signed integer with no specific constraints.

This change is a requirement to update our DRM drivers to Linux 5.12.

Differential Revision: https://reviews.freebsd.org/D37364

linuxkpi: Introduce module_param() of type `hexint`

In Linux, this affects how the value is formatted. In FreeBSD, this
remains an unsigned integer.

Reviewed by: manu
Approved by: manu
Differential Revision: https://reviews.freebsd.org/D36958

LinuxKPI: Constantly use _LINUXKPI_ prefix in include guards

MFC after: 1 week
Reviewed by: bz, emaste, hselasky, manu
Differential Revision: https://reviews.freebsd.org/D33562

LinuxKPI: add LINUXKPI_PARAM_charp()

Add yet another version of the various module_param_named() use cases.
This one deals with "charp".

Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30433

Stub kernel_param_lock() and kernel_param_unlock() in the LinuxKPI.

MFC after: 1 week
Submitted by: Johannes Lundberg <johalun0@gmail.com>
Sponsored by: Mellanox Technologies
Sponsored by: Limelight Networks

Add support for runtime modifiable module parameters in the LinuxKPI.

Linux module parameters have a permissions value. If any write bits
are set we are allowed to modify the module parameter runtime. Reflect
this when creating the static SYSCTL nodes.

Sponsored by: Mellanox Technologies
MFC after: 1 week

Add more module parameter macros to the LinuxKPI.

Obtained from: kmacy @
Sponsored by: Mellanox Technologies

Add support for boolean module parameters in the LinuxKPI.

Requested by: kmacy @
Sponsored by: Mellanox Technologies

Implement Linux module parameters as read-only tunable SYSCTLs.

Bool module parameters are no longer supported, because there is no
equivalent in FreeBSD.

There are two macros available which control the behaviour of the
LinuxKPI module parameters:

- LINUXKPI_PARAM_PARENT allows the consumer to set the SYSCTL parent
where the modules parameters will be created.

- LINUXKPI_PARAM_PREFIX defines a parameter name prefix, which is
added to all created module parameters.

Sponsored by: Mellanox Technologies
MFC after: 1 week

Finish process of moving the LinuxKPI module into the default kernel build.

- Move all files related to the LinuxKPI into sys/compat/linuxkpi and
its subfolders.
- Update sys/conf/files and some Makefiles to use new file locations.
- Added description of COMPAT_LINUXKPI to sys/conf/NOTES which in turn
adds the LinuxKPI to all LINT builds.
- The LinuxKPI can be added to the kernel by setting the
COMPAT_LINUXKPI option. The OFED kernel option no longer builds the
LinuxKPI into the kernel. This was done to keep the build rules for
the LinuxKPI in sys/conf/files simple.
- Extend the LinuxKPI module to include support for USB by moving the
Linux USB compat from usb.ko to linuxkpi.ko.
- Bump the FreeBSD_version.
- A universe kernel build has been done.

Reviewed by: np @ (cxgb and cxgbe related changes only)
Sponsored by: Mellanox Technologies