ppc4xx: Fix PMC405DE support

This patch fixes PMC405DE support. Patch 85d6bf0b fixed out-of-tree
building for this board but the loadpci object did not get linked
after that.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd.eu>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/board/esd/pmc405de/Makefile b/board/esd/pmc405de/Makefile
index 327e51e..f435495 100644
--- a/board/esd/pmc405de/Makefile
+++ b/board/esd/pmc405de/Makefile
@@ -22,12 +22,15 @@
 #
 
 include $(TOPDIR)/config.mk
+ifneq ($(OBJTREE),$(SRCTREE))
+$(shell mkdir -p $(obj)../common)
+endif
 
 LIB	= $(obj)lib$(BOARD).a
 
 COBJS-y	= $(BOARD).o
 COBJS-$(CONFIG_CMD_CHIP_CONFIG) += chip_config.o
-COBJS	+= ../common/cmd_loadpci.o
+COBJS-y += ../common/cmd_loadpci.o
 
 COBJS	:= $(COBJS-y)
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)