Remove juno/juno2 distinction
Created by: bjackman
All Juno boards now have the same hwmon setup, so we don't need the juno/juno2 distinction any more.
This supersedes https://github.com/ARM-software/lisa/pull/225 as it's quite urgent to get this fixed. Note I haven't included backwards compatibility here, people who currently use 'juno2' will need to change their config. Any objections there?