MFC 307263

hyperv/vmbus: Add __FBSDID

Sponsored by: Microsoft

MFC 303421,303422,303470-303473

303421
hyperv/vmbus: Avoid unnecessary mb()

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7333

303422
hyperv/vmbus: Inclusion cleanup

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7334

303470
hyperv/vmbus: Reindent function declarations.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7344

303471
hyperv/vmbus: Forward declare static functions

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7346

303472
hyperv/vmbus: Move driver glue to the beginning of the files

Just as most of other drivers do. And move sysinit function close
to its SYSINIT.

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7347

303473
hyperv/vmbus: Revoke unnecessary exposure of vmbus softc

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7348

MFC 303379

hyperv/vmbus: Rename cleaned up bufring code

Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7318