feat: Add MLAG/LAG logic to mock inventory script
feat: Add MLAG/LAG logic to mock inventory script

When a 'config.yml' with MLAG/LAG configuration is processed by
'mock_inventory.py' the data port MAC addresses are encoded with an 'A1'
in the second octet, the data switch list index in the third octet and
the port number in the fourth octet.

Change-Id: I58ed3dc52891b2bf920da3cf732593fd27064e46

open-power-ref-design-toolkit/cluster-genesis,open-power-ref-design-toolkit/cluster-genesis