[PATCH] x86: do not recompile boot for each build

Keep the arch/i386/boot directory from being rebuilt every time.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

arch/i386/boot/Makefile

@@ -39,7 +39,7 @@ setup-y		+= printf.o string.o tty.o video.o version.o voyager.o
 setup-y		+= video-vga.o
 setup-y		+= video-vesa.o
 setup-y		+= video-bios.o
-
+targets		+= $(setup-y)
 hostprogs-y	:= tools/build
 
 HOSTCFLAGS_build.o := $(LINUXINCLUDE)