powerpc: Merge arch/ppc64/mm to arch/powerpc/mm

This moves the remaining files in arch/ppc64/mm to arch/powerpc/mm,
and arranges that we use them when compiling with ARCH=ppc64.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/ppc64/Makefile b/arch/ppc64/Makefile
index fa88920..4a9928e 100644
--- a/arch/ppc64/Makefile
+++ b/arch/ppc64/Makefile
@@ -83,7 +83,7 @@
 
 libs-y				+= arch/ppc64/lib/
 core-y				+= arch/ppc64/kernel/ arch/powerpc/kernel/
-core-y				+= arch/ppc64/mm/
+core-y				+= arch/powerpc/mm/
 core-y				+= arch/powerpc/platforms/
 core-$(CONFIG_XMON)		+= arch/ppc64/xmon/
 drivers-$(CONFIG_OPROFILE)	+= arch/powerpc/oprofile/