Use the new userboot 'getenv' callback to set a couple of environment variables in the guest.
Use the new userboot 'getenv' callback to set a couple of environment variables
in the guest.

The variables are: smbios.bios.vendor=BHYVE and boot_serial=1

The FreeBSD guest uses the "smbios.bios.vendor" environment variable to
detect whether or not it is running as a guest inside a hypervisor.

The "boot_serial=1" is temporary and will be dropped when bhyve can do VGA
emulation.

Obtained from:	NetApp

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