pciutils: Add support for 32-bit PCI domains

pciutils: Add support for 32-bit PCI domains

This adds support for new host bridges that may create PCI domain number
values requiring more than 16 bits. The new domain 32-bit integer is
signed to allow -1 for "any", and is sufficient as the domain number
will never require the full 32-bits.

The domain field is appended at the end of struct pci_dev, and the
current location of the 16-bit domain remains for compatibility. The
domain number is truncated and copied into the legacy domain location
so existing applications linking to the library will continue to work
without modification. We accept that these applications may not work
correctly on machines with host bridges exporting 32-bit domains.

In order to force new programs to link to the new ABI, the pci_init
function call is versioned in this commit.

Signed-off-by: Keith Busch <keith.busch@intel.com>