Adding ability to configure passthrough_whitelist and alias parameters

The patch gets key:value located under nova:compute:sriov:nic_name and
nova:<role>:pci:alias:<alias1>...<aliasN> puts it to nova.conf in appropirate
format for passthrough_whitelist and alias parameters.

Change-Id: I83f505658f9e8d241a9f31b5ddc4ba7089bc51cb
Related-PROD: PROD-23653 (PROD:23653)
11 files changed