Revert "pci: prepare makefiles for pci code reorganization"

This reverts commit 475d67c3bcd6ba9fef917b6e59d96ae69eb1a9b4.

Now that all users have been updated, we don't need the
makefile hack or the softlink anymore.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>