XS RFR: 7198815 Add the minimal VM as "known" in jvm.cfg

[David Holmes]

http://cr.openjdk.java.net/~dholmes/7198815/webrev/
The minimal VM has just reached jdk8/jdk8/hotspot. This change makes it 
easy for anyone building the minimal VM to actually select it at runtime.

Only 32-bit linux platforms are targeted.

This will be pushed via the TL repo.

Thanks,
David