PCI Manager Component

[hjaensch7]

Create a PCI manager component that exports and interface that can be utilized by a unikernel such as the rumpkernel. Provides security by limiting access to the entire PCI bus, distribute devices to components at boot based on sysspec.

• Run on HW with one RK and no access scope
• Run on HW with multiple RKs and no access scope
• Run on HW with one RK with access scope
• Run on HW with multiple RKs with access scopes
• Switch from a function to a union for config data
• Cos style guide review
• General clean up
• Check BAR value restoration with assert