powerpc: Merge enough to start building in arch/powerpc.

This creates the directory structure under arch/powerpc and a bunch
of Kconfig files.  It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac.  This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.

For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel.  This makes some minor changes
to files in those directories and files outside arch/powerpc.

The boot directory is still not merged.  That's going to be interesting.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
new file mode 100644
index 0000000..347f979
--- /dev/null
+++ b/arch/powerpc/lib/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile for ppc-specific library files..
+#
+
+obj-y			:= strcase.o string.o
+obj-$(CONFIG_PPC32)	+= div64.o copy32.o checksum.o
+obj-$(CONFIG_PPC64)	+= copypage.o copyuser.o memcpy.o usercopy.o \
+			   sstep.o checksum64.o
+obj-$(CONFIG_PPC_ISERIES) += e2a.o