ppb(4) hotplug support

["Jared D. McNeill" <jmcneill%invisible.ca@localhost>]

Hey folks --

I've adapted the OpenBSD ppb hotplug support and managed to make it more 
or less work on my Eee PC. cube@ had some concerns about how PCI 
resources are allocated, so I thought I'd throw the patch out here in 
hopes that someone can improve on it.

http://ftp.netbsd.org/pub/NetBSD/misc/jmcneill/ppb-hotplug.patch

Cheers,
Jared