x86/build: Supress realmode.bin is up to date message

Supress this unnecessary message during kernel re-build:

   make[3]: 'arch/x86/realmode/rm/realmode.bin' is up to date.
Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Link: http://lkml.kernel.org/r/1397584693-15902-1-git-send-email-pefoley2@pefoley.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/realmode/rm/Makefile

@@ -52,8 +52,9 @@ $(obj)/realmode.elf: $(obj)/realmode.lds $(REALMODE_OBJS) FORCE
 OBJCOPYFLAGS_realmode.bin := -O binary
 
 targets += realmode.bin
-$(obj)/realmode.bin: $(obj)/realmode.elf $(obj)/realmode.relocs
+$(obj)/realmode.bin: $(obj)/realmode.elf $(obj)/realmode.relocs FORCE
 	$(call if_changed,objcopy)
+	@:
 
 quiet_cmd_relocs = RELOCS  $@
       cmd_relocs = arch/x86/tools/relocs --realmode $< > $@