[Makefile] Sort COBJS in lib_<arch> Makefiles

Signed-off-by: Marian Balakowicz <m8@semihalf.com>
diff --git a/lib_mips/Makefile b/lib_mips/Makefile
index 93cca7a..799eaf2 100644
--- a/lib_mips/Makefile
+++ b/lib_mips/Makefile
@@ -25,12 +25,14 @@
 
 LIB	= $(obj)lib$(ARCH).a
 
-SOBJS	=
+SOBJS-y	+=
 
-COBJS	= board.o time.o bootm.o
+COBJS-y	+= board.o
+COBJS-y	+= bootm.o
+COBJS-y	+= time.o
 
-SRCS 	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
-OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
+SRCS 	:= $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
+OBJS	:= $(addprefix $(obj),$(SOBJS-y) $(COBJS-y))
 
 $(LIB):	$(obj).depend $(OBJS)
 	$(AR) $(ARFLAGS) $@ $(OBJS)