sh7785lcr: fix out of tree build

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/board/renesas/sh7785lcr/Makefile b/board/renesas/sh7785lcr/Makefile
index b1b538c..b8e43f7 100644
--- a/board/renesas/sh7785lcr/Makefile
+++ b/board/renesas/sh7785lcr/Makefile
@@ -18,7 +18,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).a
 
 COBJS	:= sh7785lcr.o selfcheck.o rtl8169_mac.o
 SOBJS	:= lowlevel_init.o