MFC 302636-302638,302692

MFC 302636-302638,302692

302636
    hyperv/vmbus: Move channel map to vmbus_softc

    Sponsored by:   Microsoft OSTC
    Differential Revision:  https://reviews.freebsd.org/D6982

302637
    hyperv/vmbus: Remove needed bits

    Sponsored by:   Microsoft OSTC
    Differential Revision:  https://reviews.freebsd.org/D7002

302638
    hyperv/vmbus: Destroy channel list lock upon attach failure and detach.

    Sponsored by:   Microsoft OSTC
    Differential Revision:  https://reviews.freebsd.org/D7003

302692
    hyperv/vmbus: Merge hv_connection.c into hv_channel.c

    Sponsored by:   Microsoft OSTC
    Differential Revision:  https://reviews.freebsd.org/D7004

git-svn-id: svn://svn.freebsd.org/base/stable/10@307020 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f