Go mod automatically ignores the /testdata directory.
This change ensures that the rootfs for source/pci tests are not
included in the module definition.
Signed-off-by: Evan Lezar <elezar@nvidia.com>
Separate feature discovery and creation of feature labels in the pci
source.
Move pci_utils from source/internal to the source/pci package. Change
the implementation of the PciID custom rule to utilize the FeatureSource
interface of the pci source.
Also, add minimalist unit test.
