PCI I/O spaces, as well as the i80312 PMMRs. Map these regions
in early bootstrap along with the on-board device address space.
* Adjust call to i80312_sdram_bounds() for the new way the PMMRs
are defined in i80312reg.h
* Word around some serious braindamage in RedBoot -- RedBoot uses
the on-board Ethernet to TFTP the kernel image. However, it does
not stop the Ethernet before transferring control to the loaded
program. This means that if it happens to receive another packet
(broadcast/multicast/unicast), it will happily scribble over the
memory of the new running program. Work around this problem by
performing a secondary-bus-reset on the i80312's PPB. XXX This
could be problematic if we ever encounter an application where
the i80312's PPB is actually used as a passthrough PPB.
