[POWERPC] spufs: fix Makefile for "make clean"

added spu_{save,restore}_dump.h to target of 'make clean'
Signed-off-by: Masato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/cell/spufs/Makefile

@@ -15,6 +15,7 @@ SPU_AFLAGS	:= -c -D__ASSEMBLY__ -I$(srctree)/include -I$(objtree)/include2
 SPU_LDFLAGS	:= -N -Ttext=0x0
 
 $(obj)/switch.o: $(obj)/spu_save_dump.h $(obj)/spu_restore_dump.h
+clean-files := spu_save_dump.h spu_restore_dump.h
 
 # Compile SPU files
       cmd_spu_cc = $(SPU_CC) $(SPU_CFLAGS) -c -o $@ $<