Finish r254925 and remove the last remaining sysctl name list macro.  The
one port that used it has been fixed to use the more portable
getprotoent(3) instead.
Revert r256934, it needs work to build on mips32.
Make all Open Firmware internal interfaces endian-safe by using the new
OF_getencprop() API. This removes one explicit endianness conversion in
ofw_iicbus.c.
Remove OF_instance_to_package() hack for FDT and replace with use of the
generic OF_xref_phandle() API universally. Also replace some related
explicit uses of fdt32_to_cpu() with OF_getencprop() calls.
Improve SRV records support for the pkg(8) bootstrap:
- order srv records by priorities
- for all entries of the same priority, order randomly respect the weight
- select the port where to fetch from respect the port provided in the SRV record

Obtained from:	pkg git repo
MFC after:	3 days
Use OF_getencprop() in preference to OF_getprop() for numerical quantities.
Since all supported PowerPC systems are big-endian, this is a no-op, but
this is preparatory work to moving this to /sys/dev/ofw.