Remove $FreeBSD$: one-line sh pattern

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

Update Makefile.depend files

Update a bunch of Makefile.depend files as
a result of adding Makefile.depend.options files

Reviewed by: bdrewery
MFC after: 1 week
Sponsored by: Juniper Networks
Differential Revision: https://reviews.freebsd.org/D22494

Add libsecureboot

Used by loader and veriexec
Depends on libbearssl

Reviewed by: emaste
Sponsored by: Juniper Networks
Differential Revision: D16335