[POWERPC] Rename 44x bootwrapper

Rename the 44x.c wrapper file to 4xx.c.  This will allow us to add common
functions in a single file that can be shared across all of 4xx.
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>

arch/powerpc/boot/Makefile

@@ -31,7 +31,7 @@ endif
 
 BOOTCFLAGS	+= -I$(obj) -I$(srctree)/$(obj)
 
-$(obj)/44x.o: BOOTCFLAGS += -mcpu=440
+$(obj)/4xx.o: BOOTCFLAGS += -mcpu=440
 $(obj)/ebony.o: BOOTCFLAGS += -mcpu=440
 
 zlib       := inffast.c inflate.c inftrees.c
@@ -44,7 +44,7 @@ $(addprefix $(obj)/,$(zlib) gunzip_util.o main.o): \
 src-wlib := string.S crt0.S stdio.c main.c flatdevtree.c flatdevtree_misc.c \
 		ns16550.c serial.c simple_alloc.c div64.S util.S \
 		gunzip_util.c elf_util.c $(zlib) devtree.c oflib.c ofconsole.c \
-		44x.c ebony.c mv64x60.c mpsc.c mv64x60_i2c.c cuboot.c
+		4xx.c ebony.c mv64x60.c mpsc.c mv64x60_i2c.c cuboot.c
 src-plat := of.c cuboot-83xx.c cuboot-85xx.c holly.c \
 		cuboot-ebony.c treeboot-ebony.c prpmc2800.c \
 		ps3-head.S ps3-hvcall.S ps3.c