[POWERPC] Rename 4xx paths to 40x

4xx is a bit of a misnomer for certain things, as they really apply to PowerPC
40x only.  Rename some of the files to clean this up.

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 7e4d27a..bf20fa6 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -13,7 +13,7 @@
 				   hash_utils_64.o hash_low_64.o tlb_64.o \
 				   slb_low.o slb.o stab.o mmap.o $(hash-y)
 obj-$(CONFIG_PPC_STD_MMU_32)	+= ppc_mmu_32.o hash_low_32.o tlb_32.o
-obj-$(CONFIG_40x)		+= 4xx_mmu.o
+obj-$(CONFIG_40x)		+= 40x_mmu.o
 obj-$(CONFIG_44x)		+= 44x_mmu.o
 obj-$(CONFIG_FSL_BOOKE)		+= fsl_booke_mmu.o
 obj-$(CONFIG_NEED_MULTIPLE_NODES) += numa.o