OMAP3: Reorganize Makefile style

Reformat COBJS handling.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Dirk Behme <dirk.behme@googlemail.com>
diff --git a/cpu/arm_cortexa8/omap3/Makefile b/cpu/arm_cortexa8/omap3/Makefile
index b96b3dd..d1e658d 100644
--- a/cpu/arm_cortexa8/omap3/Makefile
+++ b/cpu/arm_cortexa8/omap3/Makefile
@@ -26,7 +26,13 @@
 LIB	=  $(obj)lib$(SOC).a
 
 SOBJS	:= lowlevel_init.o
-COBJS	:= sys_info.o board.o clock.o interrupts.o mem.o syslib.o
+
+COBJS	+= board.o
+COBJS	+= clock.o
+COBJS	+= mem.o
+COBJS	+= syslib.o
+COBJS	+= sys_info.o
+COBJS	+= interrupts.o
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS) $(SOBJS))