Add missing IDT entry #HV (vector 28)

[Zildj1an]

Currently the InterruptDescriptorTable is missing entry with vector number 28, #HV. See AMD's APM Vol 2 here, subsection 8.2.21.

[Zildj1an]

By the way, probably a good time to review issue #313 since I don't see mention of the #VC entry on the online documentation

[josephlr]

We'd be happy to accept a patch to add in the documentation. #313 is a good example of how to add one of these SEV-specific exceptions.

[Zildj1an]

Pull request created.

[Zildj1an]

Pull request merged.