This patches the ppc32 and ppc64 versions of the headers and .c files
with helper functions for manipulating the performance counting
hardware.  As a side effect, it removes use of the term "perfmon" from
ppc32, thus avoiding confusion with the unrelated performance counter
interface from HP Labs also called "perfmon".

Built, but not booted, for g5, pSeries, iSeries, and 32-bit Powermac
with both ARCH=powerpc and ARCH=ppc{,64} as appropriate.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!