Put 'device hyperv' back in amd64/GENERIC, incorrectly removed with r255736.
Put 'device hyperv' back in amd64/GENERIC, incorrectly removed with
r255736.

Pointed out by:	gibbs
Approved by:	re (delphij)
Sponsored by:	The FreeBSD Foundation

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase