I don't believe anyone is quite using the sparc64 kernel sources in CVS
yet -- things aren't just quite ready (but almost). So this commit should
be OK to make.
Most of the contents are commented out as they are as-yet untested.
However, I wanted the contents to match our other arches, so that when
people make changes to {i386,alpha,ia64}, they will also make the same
changes here.