Both nova-api and nova-compute depends on the [pci]alias configuration.
These services loaded and validated the config lazily when it was
needed. This can late and hard to troubleshoot failures during instance
lifecycle operations due to simple config errors.
So this patch adds an early load of this config to nova-api and
nova-compute.
Related-Bug: #2102038
Related-Bug: #2111440
Change-Id: I5d5dc912ca24979067984c7cb53ceaded7daf236