Update VMCI license based on comments from core, the FreeBSD Foundation,
and VMware legal:
- Add a dual BSD-2 Clause/GPLv2 LICENSE file in the VMCI directory
- Remove the use of "All Rights Reserved"
- Per best practice, remove copyright/license info from Makefile
Reviewed by: imp, emaste, jhb, Vishnu Dasa <firstname.lastname@example.org>
Approved by: VMware legal via Mark Peek <email@example.com>
Differential Revision: https://reviews.freebsd.org/D14979