Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

MIPS XLP platform code update.

* Update the hardware access register definitions and functions to bring
them in line with other Netlogic software.
* Update the platform bus to use PCI even for on-chip devices. Add a dummy
PCI driver to ignore on-chip devices which do not need driver.
* Provide memory and IRQ resource allocation code for on-chip devices
which cannot get it from PCI config.
* add support for on-chip PCI and USB interfaces.
* update conf files, enable pci and retain old MAXCPU until we can support
>32 cpus.

Approved by: re(kib), jmallett