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/kernel/Makefile b/arch/powerpc/kernel/Makefile
new file mode 100644
index 0000000..62c4a51
--- /dev/null
+++ b/arch/powerpc/kernel/Makefile
@@ -0,0 +1,18 @@
+#
+# Makefile for the linux kernel.
+#
+
+extra-$(CONFIG_PPC_STD_MMU)	:= head.o
+extra_$(CONFIG_PPC64)		:= head_64.o
+extra-$(CONFIG_40x)		:= head_4xx.o
+extra-$(CONFIG_44x)		:= head_44x.o
+extra-$(CONFIG_FSL_BOOKE)	:= head_fsl_booke.o
+extra-$(CONFIG_8xx)		:= head_8xx.o
+extra-$(CONFIG_6xx)		+= idle_6xx.o
+extra-$(CONFIG_POWER4)		+= idle_power4.o
+extra-$(CONFIG_PPC_FPU)		+= fpu.o
+extra-y				+= vmlinux.lds
+
+obj-y				:= semaphore.o traps.o process.o
+
+obj-$(CONFIG_ALTIVEC)		+= vecemu.o vector.o