a sub-node of nexus (ofwbus) rather than direct attach under nexus. This
fixes FDT on x86 and will make coexistence with ACPI on ARM systems easier.
SPARC is unchanged.
Reviewed by: imp, ian
fdtbus in most cases. This brings ARM and MIPS more in line with existing
Open Firmware platforms like sparc64 and powerpc, as well as preventing
double-enumeration of the OF tree on embedded PowerPC (first through nexus,
then through fdtbus).
This change is also designed to simplify resource management on FDT platforms
by letting there exist a platform-defined root bus resource_activate() call
instead of replying on fdtbus to do the right thing through fdt_bs_tag.
The OFW_BUS_MAP_INTR() and OFW_BUS_CONFIG_INTR() kobj methods are also
available to implement for similar purposes.
Discussed on: -arm, -mips
Tested by: zbb, brooks, imp, and others
MFC after: 6 weeks
