CA-114333: Allow Linux HVM guests to use >4 devices

Signed-off-by: John Else <john.else@citrix.com>
CA-151613: Pass -priv flag to qemu when doing PCI passthrough

This was originally removed on the xs64bit branch as CA-133523, but the
removal was reverted.

Signed-off-by: John Else <john.else@citrix.com>
Merge pull request #155 from johnelse/pass-priv-to-qemu

CA-151613: Pass -priv flag to qemu when doing PCI passthrough
Merge pull request #154 from johnelse/ca-114333

CA-114333: Allow Linux HVM guests to use >4 devices