hyperv/vmbus: Get rid of unnecessary definition.

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7240

hyperv/vmbus: Move IC register definition to Hyper-V utilities

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7241

hyperv/vmbus: Channel struct field rename

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7242

hyperv/vmbus: Pass channel as the first argument for channel callback

The prepares to kill device private fields in channel struct, which
are not flexible and extensible.

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7243

hyperv/vmbus: Deprecate the device private data in channel struct

They are neither flexible nor extensible.

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7244

hyperv/vmbus: Hide channel struct definition.

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7245

hyperv/vmbus: Save MNF trigger location instead of MNF trigger index.

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7246

hyperv/vmbus: Save event flag location and evet flag mask.

This avoids unnecessary access to the vmbus_softc struct on sending path.

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7257

hyperv/vmbus: Reorder channel fields.

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7258

hyperv/vmbus: Shuffle function declaration and macro definition.

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7259

hyperv: hv_vmbus_channel -> vmbus_channel

Sponsored by:   Microsoft OSTC
Differential Revision:  https://reviews.freebsd.org/D7260