PMC440 board: fix board Makefile for out-of-tree building

Signed-off-by: Wolfgang Denk <wd@denx.de>

board/esd/pmc440/Makefile

@@ -22,6 +22,9 @@
 #
 
 include $(TOPDIR)/config.mk
+ifneq ($(OBJTREE),$(SRCTREE))
+$(shell mkdir -p $(obj)../common)
+endif
 
 LIB	= $(obj)lib$(BOARD).a