deal with 24-bit addresses. While the two other attachments, namely
isa and cbus, do it properly, the PCI attachment was passing
BUS_SPACE_MAXADDR instead of BUS_SPACE_MAXADDR_24BIT. This bug
became apparent with the new contigmalloc() code.
This fixes the problem reported with lnc(4) interfaces inside VMWare,
and should theoritically also fix any user of a PCI lnc(4) card. It
is a RELENG_5 MFC candidate.
Tested by: Florian Le Goff <madflo@beertech.org>