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

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

Regularize the Netflix copyright

Use recent best practices for Copyright form at the top of
the license:
1. Remove all the All Rights Reserved clauses on our stuff. Where we
piggybacked others, use a separate line to make things clear.
2. Use "Netflix, Inc." everywhere.
3. Use a single line for the copyright for grep friendliness.
4. Use date ranges in all places for our stuff.

Approved by: Netflix Legal (who gave me the form), adrian@ (pmc files)

Fix build issue with const and volatile and the
myriad ways that the various compliers treat this. The
only safe prefetch appears to be for AMD. The other
compilers either are not volatile or are not const :(

Reported by: Michael Tuexen

Minor style nits

Use full copyright year.
Remove 'All Rights Reserved' from new file (rights holder OK'd)
Minor #ifdef motion and #endif tagging
Remove __FBSDID macro from comments

Sponsored by: Netflix
OK'd by: rrs@

Tigthen up kern_prefetch.h includes. The DMAP check was not committed in
here with HPTS so these includes aren't necessary.

Comments from rrs:
Yeah I had those in there in our version so I could
validate the range in amd64 with the DMAP_VM but for
some reason those don't work in head anymore.. Forgot
to purge the headers :)

Submitted by: Kevin Bowling
Reviewed by: rrs
Differential Revision: https://reviews.freebsd.org/D15164

This commit brings in the TCP high precision timer system (tcp_hpts).
It is the forerunner/foundational work of bringing in both Rack and BBR
which use hpts for pacing out packets. The feature is optional and requires
the TCPHPTS option to be enabled before the feature will be active. TCP
modules that use it must assure that the base component is compile in
the kernel in which they are loaded.

MFC after: Never
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D15020