abstract out the vm detection via smbios..

[jmg]

Summary

This makes the detection of VMs common between platforms that
have SMBios.

Note, I'm not sure what is correct copyright. I just added the
people who touched the code that I relocated.. Neither person had
added their own copyright to the original file.

Adding them as reviewers so they can approve/disagree w/ the
attribution.

Test Plan

Have built VMs of i386, amd64, arm64, and booted them under qemu
and verified that they all detect they are VMs. Note that I don't
have a good way to verify that i386/amd64 is using this code, as
qemu sets the HV bit in CPUID, so this code is not explicitly run.

[kib]

sys/dev/smbios/smbios_subr.c

39

Please do not add these two lines for a new file.

46

I do not think this comment is needed

49

61

[imp]

Modulo kib's comments.... this looks good...

[jmg]

implement kib's comments

[jmg]

done.

[jmg]

not sure how it included a file AFTER the commit hash, but arc is
weird.. hopefully this will work..