New function smbios_match to detect BIOS versions during boot

Motivation is to introduce BIOS specific quirks early in the boot
process. smbios_match can be called before malloc is avaible, that's
why parts of smbios_detect have been moved into a separate function
smbios_probe that will be called by smbios_detect as well as
smbios_match.

Reviewed by: jhb
Approved by: jhb
Differential Revision: https://reviews.freebsd.org/D1679