Correct display of bhyve SMBIOS UUIDs with dmidecode by bumping the version.

The mixed little/big-endianness of SMBIOS UUIDs was clarified in v2.6
of the SMBIOS spec. dmidecode uses the reported version of SMBIOS to
determine the layout and what to byte-swap.

bhyve's SMBIOS reported as 2.4 though it implemented the 2.6-style of
memory layout. This resulted in dmidecode reporting a different
UUID than one passed in via the -U option.

Fix by exporting a version of 2.6.

Reviewed by:	tychon
Reported by:	julian
MFC after:	1 day
Stage one of multipass suspend/resume

Summary:
Add the beginnings of multipass suspend/resume, by introducing
BUS_SUSPEND_CHILD/BUS_RESUME_CHILD, and move the PCI driver to this.

Reviewers: jhb

Reviewed By: jhb

Differential Revision: https://reviews.freebsd.org/D590