vfio/pci: Cleanup ROM blacklist quirk

Create a vendor:device ID helper that we'll also use as we rework the
rest of the quirks.  Re-reading the config entries, even if we get
more blacklist entries, is trivial overhead and only incurred during
device setup.  There's no need to typedef the blacklist structure,
it's a static private data type used once.  The elements get bumped
up to uint32_t to avoid future maintenance issues if PCI_ANY_ID gets
used for a blacklist entry (avoiding an actual hardware match).  Our
test loop is also crying out to be simplified as a for loop.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
