Blackfin: fix out-of-tree building with ldscripts

Many of the Blackfin board linker scripts are preprocessed, so make sure we
output the linker script into the build tree rather than the source tree.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/board/bf533-ezkit/Makefile b/board/bf533-ezkit/Makefile
index b2d7acf..6a45b7c 100644
--- a/board/bf533-ezkit/Makefile
+++ b/board/bf533-ezkit/Makefile
@@ -35,12 +35,11 @@
 OBJS	:= $(addprefix $(obj),$(COBJS))
 SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
-$(LIB):	$(obj).depend $(OBJS) $(SOBJS) u-boot.lds
+$(LIB):	$(obj).depend $(OBJS) $(SOBJS) $(obj)u-boot.lds
 	$(AR) $(ARFLAGS) $@ $(OBJS) $(SOBJS)
 
-u-boot.lds: u-boot.lds.S
-	$(CPP) $(CPPFLAGS) -D__ASSEMBLY__ -P -Ubfin $^ > $@.tmp
-	mv -f $@.tmp $@
+$(obj)u-boot.lds: u-boot.lds.S
+	$(CPP) $(CPPFLAGS) -D__ASSEMBLY__ -P $^ > $@
 
 clean:
 	rm -f $(SOBJS) $(OBJS)