[LinuxBIOS] [BUILDROM] Expand linuxbiosv3 support

[Myles Watson]

It complains that the logs directory doesn't exist when it tries to fetch
and create the linuxbiosv3/logs/fetch.log file.

I prefer to have LinuxBIOSv2 and LinuxBIOSv3 represented in the same way.  I
think it's confusing to have one be LBV3 and one LINUXBIOS.  It seems like
LINUXBIOS should be used in the generic case, and things that are specific
to v2 or v3 should be labeled that way.

Which platform uses the extra ROM functionality you added?  I didn't try
that out.

Myles